Excessive sweating: causes, symptoms and treatments

Sweating is a completely normal function of the human body, a built-in cooling system that keeps our temperature regulated. But when sweating starts dictating what you wear, where you go, and how you feel about yourself, it may point to something more. Board-certified dermatologist Dr. Shireen Idris explains the mechanisms behind sweat, when it becomes a clinical concern, and what options are available to manage it.

Why we sweat

Sweat is the body's response to heat: when body temperature rises, sweat glands release a watery secretion onto the skin that cools us down as it evaporates. Triggers include exercise, stress, spicy foods, hormonal changes (perimenopause, menopause), and certain medications.

A key fact: sweat itself has no smell. Body odor occurs when sweat interacts with bacteria on the surface of the skin.

Two types of sweat glands

Not all sweat glands are equal:

• Eccrine glands: distributed all over the body, they produce a watery, odorless secretion that helps regulate temperature. Most concentrated on palms, soles, and scalp.
• Apocrine glands: located in hair-bearing areas like underarms and groin. They develop after puberty, and their secretion produces body odor when it interacts with skin bacteria.

Understanding this distinction matters before reaching for harsh antibacterial soaps or odor-masking products.

Normal sweating vs. hyperhidrosis

Normal sweating stops when the trigger disappears. Hyperhidrosis, however, is excessive sweating that continues beyond what a given stimulus would justify.

Two main types:

• Primary hyperhidrosis: excessive sweating in specific areas (palms, feet, underarms, scalp). Usually has a genetic component and is not caused by an underlying condition.
• Secondary hyperhidrosis: widespread profuse sweating linked to other conditions such as thyroid imbalance, hormonal shifts, medications, or in rare cases, underlying tumors. Night sweats accompanied by unexplained weight loss warrant medical evaluation.

Treatment options

Over-the-counter antiperspirants

The first line of treatment is an antiperspirant, not a deodorant. Deodorants mask odor; antiperspirants reduce sweat gland activity by forming small plugs of aluminum chloride in the gland openings.

• Certain Dry (15% aluminum chloride): prescription-strength efficacy available over the counter. Apply at night for best results.
• ZABsorb: moisture-absorbing powder ideal for skin folds (under breasts, groin, feet). Does not stop sweating but reduces friction and supports the skin barrier.

Prescription options

When over-the-counter products are not enough:

• Drysol (20% aluminum chloride): higher concentration, applicable to underarms, feet, and folds.
• Cubrexa (glycopyrronium cloths): blocks the chemical signal that activates sweat glands. For underarm use only; wash hands thoroughly after applying.
• Oral glycopyrrolate: a systemic medication that reduces overall sweat activity, but may cause constipation, blurred vision, and dizziness.

Botox for hyperhidrosis

Neurotoxins like Botox and Dysport temporarily block the nerve signal (acetylcholine) that activates sweat glands. This is an FDA-approved treatment for severe primary underarm sweating when topical treatments have failed.

Effects take 10 to 14 days to appear and last 3 to 4 months. Important caution: avoid deep injections in the palms or soles to prevent temporary muscle weakness. An experienced injector is essential.

Managing body odor

Beyond antiperspirant, steps to reduce body odor:

• Use a benzoyl peroxide cleanser 3 to 4 times a week in the underarms and groin, letting it sit for a full minute before rinsing.
• Exfoliate with glycolic acid to break down skin buildup that traps bacteria in folds.
• Wash workout clothes immediately after use and avoid non-breathable synthetic fabrics like polyester.

Sweat-related skin conditions

When sweat accumulates or combines with friction and bacteria, it can trigger several conditions:

• Acne mechanica: small bumps in areas of friction and occlusion (under sports bras, along hat lines). Benzoyl peroxide wash and salicylic acid are the go-to treatments.
• Folliculitis: inflammation of the hair follicle, identifiable by a hair at the center of each bump. Can be bacterial or fungal; treatment differs by type. An antifungal shampoo like Nizoral helps with fungal folliculitis.
• Heat rash: blocked sweat ducts causing prickling and bumps. Requires cooling the skin and avoiding active ingredients like retinol or acids.
• Intertrigo: irritation in skin folds that can lead to yeast or bacterial infections. Keeping the area clean and dry is essential.

When to see a dermatologist

Seek professional care if sweating affects your mental health or social life, if your sweating patterns change suddenly, if it comes with unexplained weight loss, or if the affected area shows pain, itching, or drainage. Hyperhidrosis does not have to control your life. With the right diagnosis and tools, you can regain confidence and daily comfort.