Our body adopts several mechanisms to control its temperature. One of these mechanisms is by way of sweating. Sweat is produced through millions of sweat glands, also called as eccrine glands, located in the skin, all over our body. The maximum density of the sweat glands is on the palms, soles, armpits, groin and face. Sweating is an involuntary process controlled by the sympathetic nervous system.
Normally, sweat glands are activated in case of hyperthermia, after a workout or in conditions leading to anxiety. However, there are times when the sympathetic nervous system may become overactive and send signals to the sweat glands even in the absence of these precipitating conditions. Or, the sweat glands may work overtime as a consequence of some underlying pathology. In both these scenarios, the person sweats more than normal, a condition known as hyperhidrosis or sudorrhea.
Hyperhidrosis can be either primary or secondary depending upon its cause.
Primary Hyperhidrosis affects 2 to 3% of the population and is idiopathic in nature, i.e. its cause is not known. It is found to run in families. Primary hyperhidrosis is often limited to a specific region of the body, e.g. it can affect the palms and soles (palmo-plantar hyperhidrosis), face (facial hyperhidrosis), or the axilla (axillary hyperhidrosis). Localized hyperhidrosis usually occurs because of abnormal distribution of sweat glands. It may also be a result of a vascular pathology or it can occur when the sympathetic nerves to that particular area regenerate abnormally following their disruption due to some other reason. This form of hyperhidrosis usually begins quite early in the life, i.e. during childhood or early adolescence. Palmo-plantar variant of local hyperhidrosis is transmitted genetically through autosomal dominant genes.
Secondary Hyperhidrosis occurs as a result of some other medical condition afflicting the patient or due a dys-regulation of the autonomic nervous system. It usually starts in adulthood and one should look for specific disease or medicine that may be behind it. Secondary hyperhidrosis may be caused in multiple conditions. Some of these conditions include:
1. Physiological conditions like
2. Neurological conditions like
- Parkinson’s disease
- Arnold- Chiari malformation
- Injury to the spinal cord
- Reflex dystrophy of sympathetic nerves
Neurological conditions are usually associated with asymmetrical hyperhidrosis.
3. Metabolic conditions like
- Diabetes mellitus
- Hyperthyroidism
- Gout
- Pretibial myxedema
4. Cancers like leukemia
5. Carcinoid tumors
6. Pheocytochroma
7. Infectious diseases like tuberculosis and HIV, wherein hyperhidrosis is usually nocturnal
8. Hodgkin disease
9. Febrile illnesses
10. Diseases of the respiratory system
11. Diseases of the heart
12. Acromegaly
13. Stroke
14. Auto immune disorders like rheumatoid arthritis
15. Problems like alcoholism
16. Psychiatric and anxiety disorders
17. Herpes Zoster parotitis
18. Parotid abscess
Apart from these systemic ailments, various medications have also been found to be associated with development of symptoms of hyperhidrosis. Some of the important medications which can cause this condition include:
Psychiatric medications like tricyclic antidepressants and serotonin reuptake inhibitors
- Physotigmine
- Antihypertensive medications like propranolol
- Certain antibiotics
- Medications for treating conditions like dry mouth, etc.
- Tamoxifen, which is used in the treatment of breast cancer
Thus, we see that there could be any of these conditions which may give rise to hyperhidrosis. Therefore, whenever one complains of development of excessive sweating in the absence of an immediate provocative factor, in late adulthood, the treating physician should always keep in mind the possibility of some underlying general or metabolic condition, or some medication as the reason behind it.