Why do i sweat so much in my sleep

Overview

Night sweats, or sleep hyperhidrosis, occur when you perspire excessively during sleep without environmental heat. While occasional sweating is normal during REM sleep, excessive night sweats that drench clothing and bedding suggest an underlying cause requiring attention.

Common Medical Causes

Infections represent a major cause of night sweats. Tuberculosis historically caused night sweats and remains relevant in endemic areas. Other infections including endocarditis, pneumonia, and abscess-forming conditions produce drenching sweats. Systemic conditions like lymphoma and other cancers commonly present with significant night sweats alongside fever and weight loss.

Hormonal and Metabolic Factors

Women approaching menopause experience vasomotor symptoms causing hot flashes and night sweats due to declining estrogen levels. Hyperthyroidism increases metabolic rate and heat production during sleep. Hypoglycemia occurring at night may trigger sweating as the body responds to low blood sugar levels.

Sleep Disorders and Psychological Factors

Sleep apnea interrupts breathing repeatedly during sleep, causing arousal and compensatory sweating. Anxiety disorders and PTSD trigger sympathetic nervous system activation even during sleep. Nightmares and dream disturbances associated with trauma can precipitate excessive perspiration.

Medications and Lifestyle

Antidepressants, particularly selective serotonin reuptake inhibitors (SSRIs), frequently cause night sweats in 10-15% of users. Fever-reducing medications like aspirin create paradoxical sweating after fever breaks. Alcohol consumption before bed and caffeine use can contribute to sleep disruption and sweating.

When to Seek Medical Care

Consult a healthcare provider if night sweats persist for more than two weeks, accompany fever or weight loss, or significantly disrupt sleep quality. Medical evaluation may include thyroid testing, tuberculosis screening, and imaging studies depending on presentation.