Why Are My Feet Sweating in Bed?

If you often wake up with damp, sweaty feet, you’re not alone. Excessive foot sweating, especially at night while you’re sleeping, is a common problem that affects many people. But why exactly does this happen? Here are some of the main reasons your feet may be sweating in bed and what you can do about it.

Causes of Sweaty Feet in Bed

Temperature Regulation
One of the main jobs of sweating is to cool your body down when its core temperature rises. Your feet contain a high concentration of sweat glands, so they are primed for perspiring as a temperature regulation method.

When you’re asleep, your body temperature naturally fluctuates, often rising toward the end of sleep cycles. This triggers your sweat glands to release moisture and cool you down. Even a small increase in body heat can lead to sweaty feet. Tucked under blankets while you sleep, your feet have a harder time dissipating heat buildup.

Excessive, unpredictable sweating beyond what’s needed for temperature control is known as hyperhidrosis. This condition affects about 3% of the population. It most commonly involves the hands, feet, underarms, and face.

With hyperhidrosis, the sweat glands are overactive due to overstimulation of the sympathetic nervous system. Night sweats in the feet are a classic sign. The exact cause is usually unknown. Contributing factors can include genetics, hormones, infections, medications, stress, and more.

Socks and Bedding Fabrics
What you sleep in matters. If you wear socks to bed or sleep under thick, non-breathable blankets, your feet are more prone to getting hot and sweaty while you sleep.

Sock fabrics like polyester and nylon don’t allow much ventilation or absorption of moisture. Thick sock seams can also irritate feet and stimulate sweat production. Non-breathable bed sheets and blankets trap heat next to the skin, increasing perspiration.

Natural Sweating Rhythms
Your circadian rhythm is your body’s internal clock that regulates sleep/wake cycles and many biological processes. Sweating follows a circadian pattern too.

Sweat production tends to peak at night, especially in the early morning hours. The body may instinctively sweat more toward the end of a sleep cycle to lower temperature and prepare for waking up. Evening-dominant circadian rhythms are also linked to greater night sweats.

Hormone Changes
Shifting hormone levels during puberty, menopause, and menstrual cycles can activate sweat glands. Estrogen affects body temperature regulation. Progesterone widens blood vessels to increase heat loss. These hormonal influences may lead to hot flashes and night sweats.

Menopausal women are most likely to experience hormonal sweating at night. But hormonal changes related to thyroid disorders, diabetes, and other conditions can also increase sweating.

Anxiety and Stress
Stress triggers the “fight or flight” response, readying your body to handle perceived threats. Part of this reaction is sweating more to cool muscles and prevent overheating. Emotional and psychological stress can amp up sweat production even when your body temperature is normal.

Anxiety and stress may plague your mind at night when you’re trying to sleep. Tossing and turning can also stress your sympathetic nervous system. This stress response can come out as excessive sweating.

Medications and Substances
Certain medications and substances raise your core temperature or directly activate sweat glands:

  • Antidepressants, anti-anxiety meds, and other psychiatric drugs disrupt temperature regulation.
  • Diabetes medications, hormone treatments, NSAIDs, and chemotherapy drugs may cause sweating.
  • Nicotine and illegal stimulants like cocaine and methamphetamine are linked to night sweats.
  • Alcohol widens blood vessels and may increase perspiration. Withdrawal can also cause profuse sweating.

Underlying Conditions
Excessive night sweats, especially if they develop suddenly and affect your whole body, may result from an underlying medical condition. These include:

  • Infections like tuberculosis, endocarditis, osteomyelitis.
  • Cancers such as leukemia and lymphoma.
  • Autoimmune disorders like rheumatoid arthritis and SLE.
  • Neurological conditions including autonomic neuropathy.
  • Hypoglycemia, hormonal disorders, chronic fatigue syndrome.
  • Sleep disorders like sleep apnea.

Managing Sweaty Feet at Night

While you sleep, you can’t control bodily processes that make you sweat. But you can take steps to prevent your feet from getting so hot and damp while you sleep:

  • Keep your bedroom cool at night – around 65°F is optimal.
  • Allow your feet to get airflow – uncover them and avoid restrictive socks or leg cuffs.
  • Wear moisture-wicking socks to bed made of breathable fabrics like cotton, wool, or bamboo rayon.
  • Frequently change out your socks if they get damp.
  • Use a mattress protector and breathable, moisture-absorbing bed sheets.
  • Wash sheets frequently to minimize bacterial growth from sweat.
  • Shower before bed to wash off sweat and oils from the day.
  • Avoid heavy meals, alcohol, and rigorous exercise in the evening.
  • Relaxing yoga, meditation, or reading before bed can reduce anxiety.
  • Evaluate medications with your doctor that may increase sweating.
  • Use over-the-counter antiperspirants on dry feet at night. Prescription antiperspirants are also an option for excessive sweating issues.

Don’t let pesky sweaty feet keep bothering you at bedtime. Identify the source of the issue and take steps to stay cool, dry, and comfortable all night long. With the right adjustments, you can say goodbye to damp socks and sheets and hello to peaceful, restful sleep.