Sweating more than usual can stem from dozens of causes, ranging from a new medication or hormonal shift to an underlying health condition you haven’t identified yet. Excessive sweating affects roughly 4.8% of the U.S. population, about 15.3 million people, and it becomes more common when you factor in sweating triggered by medications or other medical conditions. The first step is figuring out whether your increased sweating is a standalone issue or a signal from your body that something else is going on.
Primary vs. Secondary Hyperhidrosis
Excessive sweating falls into two broad categories, and knowing which one applies to you changes how you approach it. Primary hyperhidrosis is sweating that happens on its own, without another medical cause. It typically starts before age 25, affects both sides of the body symmetrically, and targets specific areas: underarms, palms, soles of the feet, and the face. If you’ve always been a heavy sweater in these spots, this is likely what you’re dealing with.
Secondary hyperhidrosis is different. It’s caused by something else, whether that’s a medical condition, a medication, or a hormonal change. It can show up anywhere on the body and often affects larger areas rather than just the palms or underarms. If your sweating is new, has changed recently, or happens all over (especially at night), a secondary cause is more likely. A Swedish study found secondary hyperhidrosis in 14.8% of participants, making it nearly three times more common than the primary form.
Medications That Increase Sweating
If you started a new medication in the weeks or months before your sweating ramped up, the drug itself could be the cause. Antidepressants are among the most common culprits. SSRIs like citalopram, escitalopram, fluoxetine, and paroxetine all list excessive sweating as a side effect. Venlafaxine, a related type of antidepressant, tops the list of most frequently reported offenders in pharmacovigilance databases. Older tricyclic antidepressants like amitriptyline and imipramine can do the same thing.
Pain medications are another major category. Opioids including codeine, tramadol, morphine, oxycodone, and fentanyl all trigger sweating. Beyond these, stimulant medications like methylphenidate (used for ADHD), steroids like prednisone, and even thyroid replacement medication can shift your sweat output upward. If the timing lines up with a prescription change, bring it up with whoever prescribed it. Adjusting the dose or switching to an alternative often resolves the problem.
Hormonal Changes and Menopause
Hormones play a central role in how your body regulates temperature. When estrogen levels drop during perimenopause and menopause, the brain’s temperature control center can become overly sensitive, triggering sudden waves of heat and sweating known as hot flashes. Your body essentially loses some of its ability to accurately gauge its own temperature, so it launches a cooling response (flushing, sweating) when it doesn’t need to.
This isn’t limited to menopause. Puberty, pregnancy, and the menstrual cycle all create hormonal fluctuations that can temporarily increase sweating. If you’re in your 40s or 50s and noticing more sweating, particularly episodes that come in sudden bursts with a feeling of intense warmth, declining estrogen is a likely explanation.
Thyroid Problems and Other Medical Conditions
An overactive thyroid (hyperthyroidism) is one of the most common medical causes of new or worsening sweating. When your thyroid produces too much hormone, your metabolism speeds up, generating excess heat. Along with sweating, you might notice a rapid heartbeat, unintentional weight loss, increased sensitivity to heat, and warm, moist skin. A simple blood test can confirm or rule this out.
Diabetes can also affect sweating patterns, particularly when blood sugar drops too low. Infections, both short-term (like the flu) and chronic, raise body temperature and trigger sweat as your immune system works harder. Less commonly, certain cancers, particularly lymphoma, cause drenching night sweats as an early symptom.
Stress, Anxiety, and Your Nervous System
Emotional sweating is real, physiologically distinct, and sometimes intense enough to be mistaken for a medical problem. When you feel stressed or anxious, your brain’s hypothalamus activates the sympathetic nervous system, the same pathway responsible for the fight-or-flight response. This sends a chemical signal directly to the sweat glands, particularly in the palms, soles, underarms, and face.
The key neurotransmitter involved is acetylcholine, which binds to receptors on the sweat glands and tells them to produce sweat. This system operates independently from the sweating you do when you’re hot. That’s why you can break out in a cold sweat during a stressful meeting in an air-conditioned room. If you’ve been under more pressure than usual, or if you’ve developed anxiety that wasn’t there before, the increased sweating may be your nervous system responding to a sustained state of heightened alertness.
Night Sweats Deserve Extra Attention
Sweating during the day is one thing. Waking up with soaked sheets is another. Night sweats can be caused by many of the same triggers listed above, including medications, menopause, and anxiety. But they also serve as a red flag for conditions that need prompt evaluation.
Specific warning signs alongside night sweats include unintentional weight loss of more than 5% over six to twelve months, recurring fevers, persistent fatigue, easy bruising or unusual bleeding, and swollen lymph nodes that last longer than four to six weeks. This combination of symptoms, particularly fever, drenching sweats, and weight loss together, can indicate lymphoma or another serious condition. Swollen lymph nodes paired with ongoing night sweats are concerning enough that a biopsy shouldn’t be delayed. If your night sweats come with any of these additional symptoms, getting evaluated sooner rather than later matters.
What You Can Do About It
The right approach depends entirely on the cause. If a medication is responsible, switching or adjusting the dose is usually the simplest fix. If a thyroid condition or other medical issue is driving the sweating, treating the underlying problem typically resolves it.
For primary hyperhidrosis, where there’s no underlying cause to treat, the first step is a clinical-strength antiperspirant containing aluminum chloride. These work by temporarily blocking sweat ducts and are available both over the counter and by prescription at higher concentrations. You apply them to dry skin at night and wash them off in the morning.
When antiperspirants aren’t enough, iontophoresis is a noninvasive option that works particularly well for sweaty hands and feet. It uses a mild electrical current passed through water to reduce sweat gland activity, with symptom relief lasting up to three months after a treatment course. About half of people with primary palmar hyperhidrosis see noticeable improvement. Botulinum toxin injections are another effective option for focal sweating in the underarms, palms, or soles. The injections are given just under the skin and typically need to be repeated every four to six months, but they can dramatically reduce sweating in treated areas.
For sweating driven by stress and anxiety, the most effective route is addressing the anxiety itself, whether through therapy, lifestyle changes, or in some cases medication. Regular exercise, paradoxically, can help recalibrate your body’s sweat response over time by improving your overall thermoregulation.