Causes of Hyperhidrosis

Secondary Hyperhidrosis Causes

• The American Academy of Dermatology recommends screening for sleep disorders, such as sleep apnea, which can trigger excessive sweating 1
• Hyperthyroidism (Graves disease) causes increased metabolic rate, heat production, and compensatory sweating, according to the Pediatrics journal 2
• Heart failure and other cardiovascular diseases may present with diaphoresis, as noted in the Circulation journal 3
• Chronic kidney disease can cause uremic sweating, as stated in Praxis Medical Insights 1
• Hyperthyroidism is a major cause of hyperhidrosis, with juvenile hyperthyroidism specifically noted as decreasing exercise-heat tolerance, according to the Pediatrics journal 2
• Diabetes mellitus (particularly type 2) affects thermoregulation, as noted in the Pediatrics journal 2
• Diabetes insipidus impairs fluid balance and thermoregulation, according to the Pediatrics journal 2
• Hypoglycemia can cause hyperhidrosis, as stated in Praxis Medical Insights 1
• Pheochromocytoma can cause hyperhidrosis, as stated in Praxis Medical Insights 1
• Carcinoid syndrome can cause hyperhidrosis, as stated in Praxis Medical Insights 1
• Autonomic dysfunction can cause hyperhidrosis, as stated in Praxis Medical Insights 1
• Parkinson's disease can cause hyperhidrosis, as stated in Praxis Medical Insights 1
• Stroke can cause hyperhidrosis, as stated in Praxis Medical Insights 1
• Anticholinergic drugs affect thermoregulation, according to the Pediatrics journal 2
• Dopamine-reuptake inhibitors (used for ADHD) can impair sweating regulation, as noted in the Pediatrics journal 2
• Diuretics affect hydration status, according to the Pediatrics journal 2
• Oral retinoids (noted in dermatological conditions) can cause hyperhidrosis, as stated in the British Journal of Dermatology 4, 5, 6
• Fever from any cause increases sweating, according to the Pediatrics journal 2
• Recent illness, particularly with gastrointestinal symptoms (vomiting, diarrhea), affects hydration and thermoregulation, as noted in the Pediatrics journal 2
• Obesity increases sweating through mechanical friction at flexural sites, sweat retention, and increased pro-inflammatory cytokines, according to the British Journal of Dermatology 7
• Cystic fibrosis impairs thermoregulation, as noted in the Pediatrics journal 2
• Malignancies (lymphoma, leukemia) can cause hyperhidrosis, as stated in Praxis Medical Insights 1
• Menopause can cause hyperhidrosis, as stated in Praxis Medical Insights 1
• Congenital ichthyoses can cause hypohidrosis (reduced sweating) due to hyperkeratotic plugging of sweat ducts, though this represents impaired rather than increased sweating, according to the British Journal of Dermatology 4, 5, 6
• Hidradenitis suppurativa involves follicular occlusion and may affect sweat gland function, with obesity contributing through increased sweat retention, as noted in the British Journal of Dermatology 7
• Social anxiety disorder can manifest as hyperhidrosis, where excessive sweating occurs in response to anxiety-provoking social situations, according to the Neuropsychopharmacology journal 8, 9

Diagnostic Workup

• The American Academy of Dermatology recommends a laboratory evaluation, including complete blood count, comprehensive metabolic panel, thyroid function tests (TSH, free T4), hemoglobin A1c, serum calcium levels, vitamin D level, and iron studies, to identify secondary causes of hyperhidrosis, as stated in Praxis Medical Insights 1

Clinical Pitfalls

• Assuming all hyperhidrosis is primary without systematically excluding secondary causes, particularly thyroid dysfunction and diabetes, which are readily treatable, is a critical pitfall, as stated in Praxis Medical Insights 1
• Overlooking medication-induced hyperhidrosis is a common error, and reviewing the patient's medication list for anticholinergics, stimulants, and other agents affecting thermoregulation is essential, according to the Pediatrics journal 2
• In young patients with exercise-related sweating concerns, considering that recent illness with fever or gastrointestinal symptoms significantly impairs thermoregulation even after apparent recovery is crucial, as noted in the Pediatrics journal 2

Secondary Causes of Hyperhidrosis

Endocrine and Metabolic Causes

• Hypothyroidism and other endocrinopathies may present with altered sweating patterns, according to the American Academy of Otolaryngology-Head and Neck Surgery 10

Malignancies

• Lung cancer (or metastasis to the lung) can present with night sweats, as reported by the American Academy of Otolaryngology-Head and Neck Surgery 10
• Thyroid cancer may cause sweating disturbances, according to the American Academy of Otolaryngology-Head and Neck Surgery 10

Neurological Disorders

• Multiple sclerosis affects autonomic regulation, leading to hyperhidrosis, as noted by the American Academy of Otolaryngology-Head and Neck Surgery 10
• Myasthenia gravis and amyotrophic lateral sclerosis may present with sweating abnormalities, according to the American Academy of Otolaryngology-Head and Neck Surgery 10

Cardiovascular Causes

• Hypertension itself or medications used to treat it can cause sweating, as reported by the American Academy of Otolaryngology-Head and Neck Surgery 10

Medication-Induced Hyperhidrosis

• Antipsychotics used for schizophrenia may cause sweating, according to the American Academy of Otolaryngology-Head and Neck Surgery 10

Other Medical Conditions

• Sjögren's syndrome affects sweat gland function, as noted by the American Academy of Otolaryngology-Head and Neck Surgery 10