1. Reduced libido and sexual dysfunction: Low testosterone can decrease a man's desire for sex and can lead to erectile dysfunction, affecting intimate relationships and mental well-being.
2. Decreased muscle mass and strength: Testosterone plays a crucial role in building and maintaining muscle mass. Low levels can lead to a reduction in muscle mass and physical strength, impacting overall physical performance and body composition.
3. Increased body fat: A decrease in testosterone can alter body composition, leading to increased body fat, particularly in the abdominal area. This can increase the risk of obesity and related health conditions.
4. Bone density loss: Testosterone helps in maintaining bone density. Low levels can lead to thinner, weaker bones (osteoporosis), increasing the risk of fractures and injuries.
5. Fatigue and low energy levels: Men with low testosterone often report a significant drop in energy levels, leading to fatigue and a decrease in motivation to engage in physical and daily activities.
6. Mood swings and mental health issues: Testosterone influences mood and mental capacity. Low levels have been linked to depression, irritability, lack of focus, and reduced cognitive abilities.
7. Sleep disturbances: Low testosterone can contribute to sleep disorders, including insomnia and changes in sleep patterns, which can affect overall health and well-being.
8. Changes in hair growth: Testosterone plays a role in hair production, and low levels can lead to a loss of body and facial hair.
9. Reduced semen volume and fertility issues: Testosterone aids in the production of semen, and reduced levels can lead to a decrease in semen volume, potentially affecting fertility.

Low testosterone in men, beyond influencing physical appearance and sexual function, can also have profound implications on more serious and potentially life-threatening health conditions. Two significant health risks associated with low testosterone levels are cardiovascular disease and diabetes, which are detailed below:

Accelerated aging process

Low testosterone—a condition referred to as hypogonadism, in fact—may influence the body in several different ways that might actually add to the acceleration of aging in men. These factors are literal, including both physical and mental aspects.

Decrease in Muscle Mass and Strength: Testosterone is extremely necessary for muscle mass and strength. Its decrease can bring about a decrease in muscle mass and physical strength, both qualities usually associated with old age.

Reduced Bone Density: Testosterone helps in the production and strengthening of bones. In fact, men with low testosterone levels are likely to experience reduced bone density, which in a way pre-exposes them to osteoporosis and for that matter, fractures, which is quite rampant during old age.

Increased body fats: Low levels of testosterone can lead to the increase in body fats, especially in the tummy area. This is due to the change in body composition. He may become obese due to this change, and associated health-related problems with obesity include type 2 diabetes and cardiovascular diseases, commonly observed in the geriatric population.

Fatigue and Reduced Energy Levels: Greatly reduced energy levels coupled with complete fatigue, whereby one feels way too old for their age, and as a result, they have much less zeal to do things they previously used to be excited about, have been reported by men with low levels of testosterone.

Mood: Testosterone plays a big part in mood and the mental capacity. Low levels of testosterone could cause a man to feel depressed and irritable, and even lose interest in the things that used to bring him joy. It may also affect overall life quality perception and may cause one to feel that he is aging faster.

Drop in testosterone: Evidence indicates that low levels of testosterone may be linked to a decline in the cognitive abilities involving memory and concentration, comparable with the changes taking place during aging.

Testicular problems: Testosterones are very essential for sexual health. The inadequate level of testosterones may cause some problems, like decreased sex drive and erectile dysfunction, and sexual health problems mainly thought to occur in old ages.

Skin changes—low levels of testosterone weaken the skin, causing it to be thin, less elastic, and more predisposed to wrinkling.

Cardiovascular Disease

Low testosterone levels have been linked to an increased risk of cardiovascular diseases, including heart disease and stroke. The mechanisms through which low testosterone might influence heart health include:

• Endothelial Dysfunction: Testosterone is thought to play a role in the health of the endothelium, the inner lining of blood vessels. Low levels can lead to dysfunction of the endothelium, which can reduce the flexibility of blood vessels, impairing their ability to dilate and increasing the risk of atherosclerosis (buildup of plaque in the arteries).
• Lipid Profile Changes: Testosterone can influence lipid metabolism. Low levels of testosterone are often associated with unfavorable changes in lipid profiles, including increased levels of low-density lipoprotein (LDL) cholesterol and triglycerides, and decreased levels of high-density lipoprotein (HDL) cholesterol. These changes can contribute to the development of atherosclerosis.
• Inflammation: Low testosterone is linked to increased levels of inflammatory markers, such as C-reactive protein (CRP). Chronic inflammation is a known risk factor for cardiovascular diseases.

Diabetes

The relationship between low testosterone and type 2 diabetes has been extensively studied, and there is evidence to suggest that low testosterone levels may increase the risk of developing type 2 diabetes. Possible mechanisms include:

• Insulin Resistance: Testosterone plays a role in insulin sensitivity. Low levels of testosterone can lead to increased insulin resistance, a condition where the body's cells do not respond effectively to insulin. Insulin resistance is a key feature of type 2 diabetes.
• Fat Distribution: Men with low testosterone levels tend to have increased fat, particularly visceral fat, which is the fat stored around the abdominal organs. Visceral fat is a significant risk factor for insulin resistance and type 2 diabetes.
• Inflammatory Pathways: Similar to its role in cardiovascular disease, low testosterone can contribute to increased inflammation, which is implicated in the pathogenesis of type 2 diabetes.

It's important to recognize that these conditions are multifactorial, meaning that low testosterone is just one of many factors that can contribute to their development. Lifestyle factors such as diet, exercise, smoking status, and alcohol consumption, as well as genetic predispositions, also play significant roles.

The relationship between chronic low testosterone and the development of dementia, including Alzheimer's disease, is an area of ongoing research, with several proposed mechanisms suggesting how low testosterone might contribute to cognitive decline and dementia:

1. Neuroprotection: Testosterone is thought to have neuroprotective effects, meaning it helps protect neurons (brain cells) from damage. It may influence the growth and survival of neurons, promote the repair of damaged neurons, and protect against the accumulation of toxic substances in the brain, such as amyloid-beta plaques, which are a hallmark of Alzheimer's disease. Lower levels of testosterone could reduce these protective effects, making the brain more susceptible to damage and the development of dementia.
2. Inflammation: Chronic low testosterone may contribute to increased inflammation within the body and brain. Inflammation is a key factor in the pathogenesis of Alzheimer's disease and other forms of dementia. Testosterone has anti-inflammatory properties, and lower levels could lead to an increase in pro-inflammatory cytokines, contributing to neuroinflammation and neuronal damage.
3. Vascular Health: Testosterone plays a role in maintaining vascular health by influencing blood flow and endothelial function. Reduced testosterone levels are associated with an increased risk of cardiovascular diseases, which are known risk factors for the development of vascular dementia and can also contribute to Alzheimer's disease by affecting cerebral blood flow and leading to cerebrovascular damage.
4. Metabolic Regulation: Testosterone influences metabolism, including the regulation of insulin and glucose levels. Low testosterone levels are associated with metabolic disorders such as diabetes and obesity, which are known risk factors for Alzheimer's disease and other dementias. Insulin resistance and poor glucose metabolism can lead to brain cell damage and cognitive decline.
5. Cognitive Reserve: Chronic low testosterone may impact cognitive reserve, the brain's ability to compensate for neural damage. By affecting cognitive functions such as memory, concentration, and executive function, low testosterone may reduce the brain's resilience against the pathological changes associated with dementia.