Testosterone is an important hormone for men and is responsible for male reproductive health. It reaches a peak during the years of puberty and helps in the development of primary and secondary sexual characters. In boys, it helps to build muscles, deepens voice and boosts the size of penis and testes. Without testosterone, there would be no beards, mustaches or chest hair since it regulates hair in these places. Sperm production falls under testosterone's control too. It plays an important role during later years as well, by maintaining mood, libido, muscle mass, energy, bone density and emotional & physical health. Therefore, it is not surprising that low testosterone can cause a variety of problems in men. Testosterone decline with age is normal.

Beginning at about 40 years of age testosterone declines at a rate of 1 -1.5% per year. But, past 50, the decline will be sharper. Apart from this, the Testosterone levels may be lowered at any age by several health conditions, often noticeable by certain symptoms. How to know if you have lowered levels of testosterone? Here are some symptoms that will help you suspect if you may have lower testosterone levels:

Drop in Energy: Fatigue is one of the common effects of low testosterone. If this happens with you regularly, if you are tired all the time despite good sleep, nutritious food, and no other known medical conditions, consider getting yourself checked for testosterone levels.

Change in Sex Life: A sudden drop in your sex drive, sometimes accompanied by problems in erection (erectile dysfunction) is another common symptom of low testosterone. But you should get yourself tested to rule out other conditions, such as heart disease or diabetes, especially if you are over 35 years of age.

Fuzzy Thinking: Do you sometimes think that your thoughts are a blur? This can be a result of low testosterone. It can make you feel stressed, sad and even depressed, resulting in concentration problems. Low testosterone can also impact your memory.

Mood Change: Testosterone directly impacts your mood, even leading to extreme sadness or psychological depression. If nothing seems to make you happy, if you are not what you used to be, then visit a doctor.

Muscle Change: Muscle mass and strength reduces over the years. As testosterone helps build muscle, low levels may be the cause if you witness a sudden drop in muscle mass.
More Body Fat: If you have been enjoying healthy weight most of your life, but suddenly started gaining weight, it might point towards low testosterone in the body. Also, if you are unable to lose weight even on a healthy diet, consider consulting a doctor.

Many of these signs mirror other health conditions as well. So, one should not jump to conclusions on experiencing these symptoms. If you experience two or more of them, consult a doctor in person and get a medical evaluation.

Testosterone is described as a male sex hormone vital to the growth and maintenance of muscles, bone, hair growth and sperm production. Low levels of this hormone in men may result into a range of ailments starting from issues related to sexual drive, hair production, sperm quality, muscle and bone health and even depression. Much to our surprise, experts at the California Institute of Technology have found an association between the male hormone and decision making ability in men."What we found was the testosterone group was quicker to make snap judgements on brain teasers where your initial guess is usually wrong. Testosterone either inhibits the process of mentally checking your work or increases the intuitive feeling that 'I'm definitely right," said Colin Camerer, Professor at Caltech, reported by PTI.

Experts believed the study can pave way to further examine the negative effects of the growing testosterone-replacement therapy industry, which is primarily aimed at reversing the decline in sex drive many middle-aged men experience.

The study was conducted on nearly 250 men who were divided in groups that received a dose of placebo or testosterone gel. The participants were directed to take a cognitive reflection test along with a task that tested them on engagement, analytical skills and level of motivation. It was found that men who received hormonal doses ended up performing poorly in tests and answered 20 per cent fewer questions correctly as compared to the group that was given placebo. The testosterone group also "gave incorrect answers more quickly, and correct answers more slowly than the placebo group," the researchers wrote in the study published in the journal Psychological Science.

The same effect was not seen in the results of the basic math tests administered to both groups. The results "demonstrate a clear and robust causal effect of (testosterone) on human cognition and decision-making," researchers said. They believe that the phenomenon they have observed can be linked to testosterone's effect of increasing confidence in humans.

Low levels of testosterone in men could be associated with chronic diseases such as diabetes and hypertension, even among those 40 years of age and younger, new research has found.

The total levels of the hormone is commonly associated with just sexual health and muscle mass preservation.

The new study, published in the journal Scientific Reports, suggests that the declining levels of testosterone “could be contributing to a silent decline in overall health and increased risk for chronic disease”, said lead author of the study Mark Peterson, Assistant Professor at the University of Michigan in the US.

Using data from the US National Health and Nutrition Examination Survey, the research team examined the extent to which hypogonadism, which occurs when the body’s sex glands produce little or no hormones, is prevalent among men of all ages.

The team examined the prevalence of nine chronic conditions, including Type-2 diabetes, arthritis, cardiovascular disease, stroke, pulmonary disease, high triglycerides, hypercholesterolemia, hypertension and clinical depression among more than 2,000 men in the survey who were at least 20 years old.

The researchers studied the prevalence of multimorbidity, or when two or more of the chronic conditions were present, among three age groups (young, middle-aged and older men) with and without testosterone deficiency.

They found that low total testosterone was associated with multimorbidity in all age groups — but it was more prevalent among young and older men with testosterone deficiency.

“Men should be concerned about declining total testosterone, even if it has not reached a level to warrant a clinical diagnosis (less than 300 nanograms per deciliter),” Peterson said.

Low testosterone and age
When you think of declining levels of testosterone, you might think of middle-aged or older men. But men under 30 can also experience low testosterone, or “low T.”

According to the Mayo Clinic, testosterone levels tend to peak in men during adolescence and early adulthood. Those levels typically decline by about 1 percent each year, starting around age 30. But in some cases, you may experience declining testosterone at a younger age.

Low T is a medical condition where your body doesn’t produce enough of the hormone testosterone. Both men and women produce testosterone, but it’s called the “male hormone” because men produce a lot more of it. It’s critical for many male characteristics, including the maturation of male sex organs, sperm development, muscle mass development, voice deepening, and hair growth. Low T can cause a variety of symptoms, including erectile dysfunction, infertility, muscle mass loss, fat gain, and balding.

If you think you might be experiencing low T, make an appointment with your doctor. In some cases, it is caused by unhealthy lifestyle habits that you can change. In other cases, it is caused by an underlying medical condition that requires treatment. Your doctor can help you identify the cause of your symptoms and learn how to manage them.