Sweat is a fluid that is secreted by two types of glands present in the skin: eccrine glands and apocrine glands. The eccrine sweat glands are present in the skin throughout the body. These glands secrete a thin fluid that contains water and salts. The secretions from eccrine sweat glands are released directly on the surface of the skin, and are typical of the sweat that we normally encounter.
The apocrine sweat glands secrete a fluid that is thicker than the fluid secreted by the eccrine sweat glands. This is due to the presence of fatty substances in the secretion of apocrine sweat glands. The fluid produced by the apocrine sweat glands in the skin is secreted via the hair follicles. Sebaceous glands in the skin also secrete their oily secretions (known as sebum) via the hair follicles. However, the secretions of sebaceous glands and apocrine sweat glands are distinct. Sebum is not sweat.
Why do humans sweat?
Humans are homeothermic (or warm-blooded) animals. The biological processes within our body are designed to work within a very narrow range of temperatures. Consequently, the human body has evolved certain homeostatic mechanisms to maintain a stable core body temperature in both hot and cold environments.
Sweating is a natural thermoregulatory mechanism that is aimed at cooling down the body in hot environmental conditions. However, excessive sweating (technically referred to as hyperhidrosis) can also occur for reasons that are not related to thermoregulation.
Regardless of the cause, excessive sweating is a very uncomfortable feeling that can affect the daily functioning of an individual. Excessive sweating may also be accompanied by an offensive body odor that can adversely affect the social life of an individual. Even the sight of excessive sweat may cause people to keep a distance from the affected individual.
Sweating occurs through the skin in all areas of the body. However, some areas of the body are more sweaty than others. The back is one of the areas where excessive sweating is experienced quite often. Hyperhidrosis refers to abnormally excessive sweating that is different from copious sweating caused by strenuous physical exercise and exposure to a hot environment.
Hyperhidrosis is a medical condition in which the amount of sweating exceeds the body’s requirements for thermoregulation. When excessive sweating occurs in certain illnesses, the condition is referred to as diaphoresis. An example of diaphoresis is excessive sweating that occurs along with fever in infectious conditions.
Read more on sweaty palms.
Causes of Sweaty Back
Not all cases of excessive perspiration are abnormal. Some people naturally sweat more than others in similar environmental conditions. Sweating is a result of stimulation of the sweat glands by nerve signals from the central nervous system. The stimulation of sweat glands can occur due to environmental/physical, hormonal, psychological, neurological and infectious stimuli.
Consumption of certain medications and other substances can also stimulate sweating. As long as the perspiration occurs due to a normal physiological response to an appropriate stimulus such as heat, the sweating is considered normal.
In hyperhidrosis, excessive sweating occurs not just with normal heat stimulus but also in cold weather. Hyperhidrosis can either affect the skin on the entire body or only the skin in a specific region of the body. Hyperhidrosis that is restricted to a specific region of the skin (such as the back) is technically referred to as focal hyperhidrosis. Apart from the back, focal hyperhidrosis also frequently affects the skin on the chest and in the armpits.
Lifestyle factors play an important role in determining how much a person sweats. Physical activity increases sweating, especially in hot climates. Also, the type of clothes one wears also influences the amount of sweating.
For example, a person who dresses up in clothes that do not allow escape of body heat will sweat more than a person who wears loose-fitting clothes that allow exchange of heat with the environment. Obese people also tend to sweat more. This is due to the insulating nature of the subcutaneous fat that prevents loss of body heat.
Stress and other strong emotional mental states such as fear, anxiety, embarrassment and anger, can trigger profuse sweating. Sweating during stress is also accompanied by dilation of pupils, increased heart rate, and increased blood glucose level. The stress response is mediated by both hormones and neuronal signals.
As mentioned in the psychological causes above, hormonal stimulation can cause excessive sweating. One of the common causes of excessive sweating is hyperactivity of the thyroid gland (technically referred to as hyperthyroidism). Increased thyroid activity speeds up metabolic processes, leading to excessive heat generation and sweating.
Other hormonal disorders that may cause excessive sweating include an overactive pituitary gland and glycemia (in diabetics). In women, hormonal changes during menopause can cause excessive sweating. This condition is commonly referred to as “hot flashes”.
Read more on hypoglycemia.
Sweating occurs when sweat glands are stimulated by nerve signals. An overstimulation of the sweat glands can, therefore, cause excessive sweating. Abnormally high nervous stimulation of the sweat glands can occur due to problems in the thermoregulatory centers of the brain. A variety of neurological conditions, such as traumatic brain injury, spinal cord injury, stroke, Parkinson’s disease, and peripheral neuropathy can cause excessive sweating.
A variety of drugs and other substances can cause excessive sweating by stimulating the thermoregulatory regions of the brain, dilation of cutaneous blood vessels, and heat generation via increased metabolic activity. Examples of such sweat-inducing substances include diabetes medications, weight loss medications, illicit drugs (like ecstasy), alcohol and coffee.
Excessive sweating may also occur in conditions such as shock, heart disease, cancer, and substance withdrawal.
Remedies for Sweaty Back
Treatment for a sweaty back requires proper diagnosis of the underlying cause. When the cause of focal hyperhidrosis is not known, the condition is difficult to treat. In severe cases, surgical excision of the nerves innervating the sweat glands of the affected skin area may help. However, this is usually the last resort.
- Daily wear made of light-colored, thin material may help in reducing the buildup of heat on the surface of the skin.
- Intake of stimulants such as caffeine and nicotine should be reduced or stopped.
- Weight loss may help obese people with a sweaty back problem.
- For stress management, relaxation and coping skills can be helpful.