Overview
Polysomnography, also called a sleep study, is a test used to diagnose sleep disorders. Polysomnography records your brain waves, the oxygen level in your blood, heart rate and breathing, as well as eye and leg movements during the study.

Polysomnography is usually done at a sleep disorders unit within a hospital or at a sleep center. The test records your nighttime sleep patterns. Polysomnography is occasionally done during the day to accommodate shift workers who habitually sleep during the day.

In addition to helping diagnose sleep disorders, polysomnography may be used to help adjust your treatment plan if you've already been diagnosed with a sleep disorder.

Why it's done
Polysomnography monitors your sleep stages and cycles to identify if or when your sleep patterns are disrupted and why.

The normal process of falling asleep begins with a sleep stage called non-rapid eye movement (NREM) sleep. During this stage, your brain waves, as recorded by electroencephalography (EEG), slow down considerably.

Your eyes don't move back and forth rapidly during NREM, in contrast to later stages of sleep. After an hour or two of NREM sleep, your brain activity picks up again, and rapid eye movement (REM) sleep begins. Most dreaming occurs during REM sleep.

You normally go through multiple sleep cycles a night, cycling between NREM and REM sleep in about 90 minutes. Sleep disorders can disturb this sleep process.

Your doctor may recommend polysomnography if he or she suspects you have:

Sleep apnea or another sleep-related breathing disorder. In this condition, your breathing repeatedly stops and starts during sleep.
Periodic limb movement disorder. In this sleep disorder, you involuntarily flex and extend your legs while sleeping. This condition is sometimes associated with restless legs syndrome.
Narcolepsy. You experience overwhelming daytime drowsiness and sudden attacks of sleep in this condition.
REM sleep behavior disorder. This sleep disorder involves acting out dreams as you sleep.
Unusual behaviors during sleep. Your doctor may perform this test if you do unusual activities during sleep, such as walking, moving around a lot or rhythmic movements.
Unexplained chronic insomnia. If you consistently have trouble falling asleep or staying asleep, your doctor may recommend polysomnography.
Risks
Polysomnography is a noninvasive, painless test. The most common side effect is skin irritation caused by the adhesive used to attach test sensors to your skin.

How you prepare
You may be advised to avoid drinks or food containing alcohol or caffeine during the afternoon and evening before polysomnography. Alcohol and caffeine can change your sleep patterns, and they may make symptoms of some sleep disorders worse.

Napping in the afternoon before a sleep study is discouraged. You'll usually be asked to bathe or shower before your sleep study. But don't put on lotions, gels, colognes or makeup before the test, as these can interfere with the use of the electrodes.

What you can expect
During polysomnography
You arrive at the sleep center in the evening for polysomnography and stay overnight. You may bring items you use for your bedtime routine, and you can sleep in your own nightclothes.

The room where polysomnography is done is similar to a hotel room, and it's dark and quiet during the test. You won't share the room with anyone else. Each room has its own bathroom.

The sleeping area will typically have a low-light video camera, so the polysomnography technologists monitoring you can see what's happening in the room when the lights are out. It also has an audio system, so they can talk to you and hear you from their monitoring area outside the room.

After you get ready for bed, one of the technologists will place sensors on your scalp, temples, chest and legs using a mild adhesive, such as glue or tape. The sensors are connected by wires to a computer, but the wires are long enough to let you move around in bed. A small clip also is placed on your finger or ear to monitor the level of oxygen in your blood.

While you sleep, a technologist monitors your:

Brain waves
Eye movements
Heart rate
Breathing pattern
Blood oxygen level
Body position
Chest and abdominal movement
Limb movement
Snoring and other noise you may make as you sleep
Polysomnography technologists monitor you throughout the night. If you need assistance, you can talk to them through the monitoring equipment. They can come into the room to detach the wires if you need to get up during the night.

During the study, the technologist may have you try a positive airway pressure (PAP) machine for sleep apnea. This is a device that consists of a tight-sealing nosepiece through which a gentle stream of air is delivered to enhance your breathing.

Continuous positive airway pressure (CPAP) is one type of PAP machine. CPAP devices deliver a constant stream of air that keeps the airway passages open while you sleep.

For some people, bi-level positive airway pressure (biPap or bPap) machines may be a more comfortable choice. These devices deliver more pressure while you're breathing in, and lower pressure when you exhale.

You may have the opportunity to try on a PAP device before the sleep study begins so that you are not surprised by it if the technologist suggests you try the device later in the night. If necessary, oxygen also may be used during the study to bolster your breathing.

Although you probably won't fall asleep as easily or sleep as well at the sleep center as you do at home, this usually doesn't affect the test results. A full night's sleep isn't required to obtain accurate polysomnography results.

After polysomnography
In the morning, the sensors are removed, and you may leave the sleep center. You're given an appointment for a follow-up visit with the doctor who recommended the test. You can return to your usual activities after polysomnography

Results
The measurements recorded during polysomnography provide a great deal of information about your sleep patterns. For example:

Brain waves and eye movements during sleep can help your health care team assess your sleep stages and identify disruptions in the stages that may occur due to sleep disorders such as narcolepsy and REM sleep behavior disorder.
Heart and breathing rate changes and changes in blood oxygen that are abnormal during sleep may suggest sleep apnea.
Correct settings for PAP or oxygen in case your doctor would like to prescribe these for home use.
Frequent leg movements that disrupt your sleep may indicate periodic limb movement disorder.
Unusual movements or behaviors during sleep may be signs of REM sleep behavior disorder or another sleep disorder.
The information gathered during polysomnography is evaluated first by a polysomnography technologist, who uses the data to chart your sleep stages and cycles. Then that information is reviewed by your sleep center doctor.

At a follow-up appointment, your doctor reviews the results with you. Based on the data gathered, your doctor will discuss any treatment or further evaluation that you may need.

What is a skull X-ray?
A skull X-ray is an imaging test doctors use to examine the bones of the skull, including the facial bones, the nose, and the sinuses. See a Body Map of the skull.

It's an easy, quick, and effective method that has been used for decades to help doctors view the area that houses your most vital organ your brain.

Why a skull X-ray is done
Prior to your X-ray, your doctor will tell you the exact reason for your X-ray. A skull X-ray is typically done after a traumatic head injury. The X-ray allows your doctor to inspect any damage from the injury.

Other reasons you may undergo a skull X-ray include:

decalcification of the bone
deformities in the skull
fractures of the skull or facial bones
frequent headaches
infection of the bones of the skulls
occupational hearing loss (caused by your job)
tumors

How to prepare for a skull X-ray
X-rays require little preparation on your part.

Before the X-ray, you may need to undress from the waist up and change into a hospital gown. You may be able to keep your clothing on if your clothing doesn't have metal snaps or zippers.

You'll have to remove any jewelry, eyeglasses, and other metals from around your head. This includes necklaces and earrings. Metal can interfere with the clarity of the X-ray image.

Inform your doctor if you have any kind of surgically implanted device, such as a metal plate in your head, an artificial heart valve, or a pacemaker. Even though these things might interfere somewhat with the image, your doctor may still choose to perform an X-ray.

Other scans, such as an MRI, can be risky for people with metal in their bodies.

How a skull X-ray is performed
An X-ray is performed in a special room with a movable X-ray camera attached to a large metal arm. It's designed to be able to take multiple X-rays of various body parts.

For a skull X-ray, you'll sit in a chair or lie down on a specialized table. A drawer under the table contains the X-ray film or a special sensor that helps record the images on a computer. A lead apron will be placed over your body, which will protect your body (especially the genital region and breasts) from radiation.

The X-ray technician may have you lie on your back to start, but you'll have to change positions so the camera can capture front and side views. While the images are being taken, you'll be asked to hold your breath and stay very still. You won't feel the X-ray pass through you.

The procedure should take about 20 to 30 minutes. Once the test is complete, you can go about your day as you normally would.

The risks of a skull X-ray
While X-rays use radiation, none of it remains in your body when the test is done. Doctors argue that the benefits of the test outweigh any risk from exposure to the minimal amount of radiation produced.

However, while the level of exposure is considered safe for adults, repeated exposure may not be safe for developing fetuses. If you're pregnant or trying to get pregnant, talk to your doctor.

Results and following up after a skull X-ray
A radiologist and your doctor will go over the images, which are usually developed on large sheets of film.

As the radiation passes through your body onto the film, denser materials, such as bone and muscle, appear white. Tumors and other growths may also appear white. When presented against a lit background, your doctor and radiologist will be able to determine any problems.

Overview
A skin biopsy removes cells or skin samples from the surface of your body. The sample taken from a skin biopsy is examined to provide information about your medical condition. A doctor uses a skin biopsy to diagnose or rule out certain skin conditions and diseases.

Three main types of skin biopsies are:

Shave biopsy. A doctor uses a tool similar to a razor to remove a small section of the top layers of skin (epidermis and a portion of the dermis).
Punch biopsy. A doctor uses a circular tool to remove a small section of skin including deeper layers (epidermis, dermis and superficial fat).
Excisional biopsy. A doctor uses a small knife (scalpel) to remove an entire lump or an area of abnormal skin, including a portion of normal skin down to or through the fatty layer of skin.
Why it's done
A skin biopsy is used to diagnose or rule out skin conditions and diseases. It may also be used to remove skin lesions.

A skin biopsy may be necessary to diagnose or to help treat skin conditions and diseases, including:

Actinic keratosis
Bullous pemphigoid and other blistering skin disorders
Dermatitis, psoriasis and other inflammatory skin conditions
Skin cancers, including basal cell carcinoma, squamous cell carcinoma and melanoma
Skin infection
Skin tags
Suspicious moles or other growths
Warts
Risks
A skin biopsy is a generally safe procedure, but complications can occur, including:

Bleeding
Bruising
Scarring
Infection
Allergic reaction to the topical antibiotic
How you prepare
Before the skin biopsy, tell your doctor if you:

Have been diagnosed with a bleeding disorder
Have experienced excessive bleeding after other medical procedures
Are taking blood-thinning medications, such as aspirin, aspiring-containing medications, warfarin (Coumadin) or heparin
Have a history of skin infections, including impetigo
Are taking medications that suppress the immune system, such as diabetes medications or medications used after an organ transplant
What you can expect
Depending on the location of the skin biopsy, you may be asked to undress and change into a clean gown. A doctor or nurse then cleans the area of the skin to be biopsied. Your skin may be marked with a surgical marker or marking pen to outline the biopsy area.

You then receive a local anesthetic to numb the biopsy site. This is usually given by injection with a thin needle. The numbing medication can cause a burning sensation in the skin for a few seconds. Afterward, the biopsy site is numb and you shouldn't feel any pain or discomfort during the skin biopsy.

During the skin biopsy
What you can expect during your skin biopsy depends on the type of biopsy you'll undergo.

For a shave biopsy, your doctor uses a sharp tool, double-edged razor or scalpel to cut the tissue. The depth of the incision varies depending on the type of biopsy and the part of the body being biopsied. A shave biopsy causes bleeding. Bleeding is stopped by applying pressure to the area or by a combination of pressure and a topical medication applied to the biopsy site.
For a punch biopsy or an excisional biopsy, the procedure involves cutting into the top layer of fat beneath the skin, so stitches may be needed to close the wound. A dressing or adhesive bandage is then placed over the site to protect the wound and prevent bleeding.
A skin biopsy typically takes about 15 minutes total, including the preparation time, dressing the wound and instructions for at-home care.

After the skin biopsy
Your doctor may instruct you to keep the bandage over the biopsy site until the next day. Occasionally, the biopsy site bleeds after you leave the doctor's office. This is more likely in people taking blood-thinning medications. If this occurs, apply direct pressure to the wound for 10 to 20 minutes. If bleeding continues, contact your health care provider.

All biopsies cause a small scar. Some people develop a prominent, raised scar. The risk of this is increased when a biopsy is done on the neck or upper torso, such as the back or chest. Initially, the scar will be pink and then fade to white or sometimes brown. Scars fade gradually. The scar's permanent color will be evident one or two years after the biopsy.

Try not to bump the biopsy site area or do activities that might stretch the skin. Stretching the skin could cause the wound to bleed or enlarge the scar.

Healing of the wound can take several weeks, but is usually complete within two months. Wounds on legs and feet tend to heal slower than those on other areas of the body.

How to care for the biopsy site while it heals:

Wash your hands with soap and water before touching the biopsy site.
Wash the biopsy site with soap and water. If the biopsy site is on your scalp, use shampoo.
Rinse the site well.
Pat the site dry with a clean towel.
Cover the site with an adhesive bandage that allows the skin to ventilate.
Continue caring for the biopsy site until the stitches are removed. For shave biopsies that don't require stitches, continue wound care until the skin is healed.

Results
After the biopsy procedure, your doctor sends the sample to a laboratory for testing. Depending on the skin condition, type of biopsy and the laboratory procedures, results may take several days or a couple of weeks. Results of biopsies for metabolic or genetic testing can take several months or more.

Your doctor may schedule an office appointment to discuss the results of the test. If possible, bring along a family member or friend. It can be difficult to absorb all the information provided during an appointment. The person who accompanies you may remember something that you forgot or missed.

Write down questions that you want to ask your doctor. Don't be afraid to ask questions or to speak up when you don't understand something. Questions you may want to ask include:

Based on the results, what are my next steps?
What kind of follow-up, if any, should I expect?
Are there any factors that might have affected the results of this test and, therefore, may have altered the results?
Will I need to repeat the test at some point?
If the skin biopsy showed skin cancer, was all of the cancer removed, or will I need additional treatment?

What is a sinus X-ray?
A sinus X-ray is an imaging test that uses X-rays to look at your sinuses. The sinuses are air-filled pockets (cavities) near your nasal passage.

X-rays use a small amount of radiation to create images of your bones and internal organs. X-rays are most often used to find bone or joint problems, or to check the heart and lungs. A sinus X-ray is one type of X-ray.

A sinus X-ray is simple and quick, and does not involve any instruments that are put into your body (noninvasive). It can give your healthcare provider useful information. But a sinus X-ray can only tell your provider that a problem exists. It does not show a specific cause of the problem.

A CT scan or MRI may give better images of your sinuses. You may have one of these scans instead of a sinus X-ray in certain cases.

Why might I need a sinus X-ray?
You may need a sinus X-ray if your healthcare provider thinks that you may have:

Injury to your sinuses
Inflammation (sinusitis)
Infection
Hemorrhage
Tumor or other mass
You may also need a sinus X-ray after sinus surgery.

Your provider may have other reasons to recommend a chest X-ray.

What are the risks of a sinus X-ray?
You may want to ask your healthcare provider about the amount of radiation used during the test. Also ask about the risks as they apply to you.

Consider writing down all X-rays you get, including past scans and X-rays for other health reasons. Show this list to your provider. The risks of radiation exposure may be tied to the number of X-rays you have and the X-ray treatments you have over time.

Tell your healthcare provider if you are pregnant or think you may be pregnant. Radiation exposure during pregnancy may lead to birth defects. If you need to have a sinus X-ray, the technologist will take special care to keep the radiation exposure to the fetus at a minimum.

You may have other risks depending on your specific health condition. Be sure to talk with your provider about any concerns you have before the procedure.

How do I get ready for a sinus X-ray?
Your healthcare provider will explain the procedure to you. Ask him or her any questions you have about the procedure.
You do not need to stop eating or drinking before the test. You also will not need medicine to help you relax (sedation).
Tell your healthcare provider if you are pregnant or think you may be pregnant.
Tell your healthcare provider an artificial (prosthetic) eye. An artificial eye can create a confusing shadow on a sinus X-ray.
Follow any other instructions your provider gives you to get ready.
What happens during a sinus X-ray?
You may have a sinus X-ray as an outpatient or as part of your stay in a hospital. The way the test is done may vary depending on your condition and your healthcare provider's practices.

Generally, a sinus X-ray follows this process:

You will be asked to remove any jewelry or other objects that may get in the way of the test.
You will lie on an X-ray table. Your head will be carefully placed between the X-ray machine and the X-ray film. A foam vise will hold your head still. The vise does not hurt.
The technologist may cover the rest of your body with a lead apron (shield) so you are not exposed to the X-rays.
The technologist will ask you to hold still for a few moments while the X-ray is made.
If the X-ray is needed to look at a possible injury, the technologist will take special care to prevent further injury. For example, you may wear a neck brace if your healthcare provider thinks you have a cervical spine fracture.
Some sinus X-ray studies may require you to be in several different positions. It is very important to remain still during the X-ray. Any movement may affect the quality of the image. You may need to have another X-ray done in that case.
The technologist will step behind a special window while the image is taken.
The sinus X-ray is not painful. But you may have some discomfort or pain from moving into different positions if you have had recent surgery or an injury. The technologist will use all possible comfort measures and do the scan as quickly as possible to minimize any discomfort or pain.

What happens after a sinus X-ray?
You do not need any special care after a sinus X-ray. Your healthcare provider may give you other instructions, depending on your situation.

Next steps
Before you agree to the test or the procedure make sure you know:

The name of the test or procedure
The reason you are having the test or procedure
What results to expect and what they mean
The risks and benefits of the test or procedure
What the possible side effects or complications are
When and where you are to have the test or procedure
Who will do the test or procedure and what that person's qualifications are
What would happen if you did not have the test or procedure
Any alternative tests or procedures to think about
When and how will you get the results
Who to call after the test or procedure if you have questions or problems
How much will you have to pay for the test or procedure

Sigmoidoscopy (Anoscopy, Proctoscopy)
Test Overview
Anoscopy, proctoscopy, and sigmoidoscopy tests allow your doctor to look at the inner lining of your anus, your rectum, and the lower part of the large intestine (colon). These tests are used to look for abnormal growths (such as tumors or polyps), inflammation, bleeding, hemorrhoids, and other conditions (such as diverticulosis).

These tests use different scopes look at different sections of the colon.

Anoscopy. During an anoscopy, a short, rigid, hollow tube (anoscope) that may contain a light source is used to look at the last 2 in. (5 cm) of the colon (anal canal). Anoscopy can usually be done at any time because it does not require any special preparation (enemas or laxatives) to empty the colon.
Proctoscopy. During a proctoscopy, a slightly longer instrument than the anoscope is used to view the inside of the rectum. You will probably have to use an enema or laxative to empty the colon before the test is done.
The proctoscope is about 10 in. (25 cm) to 12 in. (32 cm) long and 1 in. (2.5 cm) wide. It allows your doctor to look into the rectum and the bottom part of the colon, but it does not reach as far into the colon as the flexible sigmoidoscope.
Sigmoidoscopy. During a sigmoidoscopy, a lighted tube is inserted through the anus. Your doctor can remove small growths and collect tissue samples (biopsy) through a sigmoidoscope. You will have to use an enema or laxative (or both) to empty the colon before the test is done.
The flexible sigmoidoscope is about 2.3 ft (70 cm) long and 0.5 in. (1 cm) wide with a lighted lens system. This instrument allows your doctor to see around bends in the colon.
Flexible sigmoidoscopy is one of many tests that may be used to screen for colon cancer. Which screening test you choose depends on your risk, your preference, and your doctor. Talk to your doctor about what puts you at risk and what test is best for you.