Sweaty Hands
What Are Eccrine Sweat Glands in the Palms?
Eccrine glands are the body's main sweat glands, small coiled tubes that open directly onto the skin. In the palms they are unusually dense, releasing thin, watery sweat that responds mainly to nervous-system alertness rather than heat. They are the reason palms feel damp under focus or nerves and stay largely odorless.
The eccrine gland is the workhorse of ordinary sweating everywhere on the body, and it appears in especially large numbers in the palms.
This entry explains what those palmar eccrine glands are and why they behave the way they do.
What eccrine glands are
Eccrine glands are small tubular structures in the dermis, coiled at the deep end and opening as a straight pore onto the skin surface. They release a thin, watery secretion made mostly of water, salts, and trace amounts of other compounds.
They are found across almost the entire body, but their density varies enormously. The palms, along with the soles and the forehead, carry them at some of the highest concentrations found in human skin.
What makes the palmar version distinctive
Palmar eccrine glands share the basic anatomy of eccrine glands elsewhere, but their density is roughly three to four times higher than an average forearm patch, and their innervation is unusually responsive to emotional and mental arousal.
The nerves that supply them are sympathetic but use acetylcholine as their neurotransmitter, which is one of the small anatomical quirks of the sweat system. It is a detail more than a practical consideration, but it is part of why palm sweat has its own predictable pattern.
There are no apocrine or sebaceous glands and no hair follicles on the palm, so palmar eccrine glands are the sole source of moisture on that skin. That is why palm sweat is watery, near-odorless, and immediately noticeable when it appears.
Their role, in short
Across the body eccrine glands are principally about cooling. On the palm the picture is a little different: the palmar version is thought to have a role in fine motor grip, keeping the skin slightly damp so it can respond to and hold onto textured surfaces.
That evolutionary theory is why some researchers describe palm sweat as 'grip sweat' rather than cooling sweat, and it is consistent with palms sweating under focus rather than heat.
Frequently asked questions
How many eccrine glands are in the palm?
Estimates vary, but the palm is often cited at several hundred glands per square centimeter, one of the highest densities on the body, alongside the sole of the foot. Exact figures depend on how they are counted and where on the palm the sample is taken.
Are palmar eccrine glands different from underarm sweat glands?
They are the same basic gland type in both places, but the underarm also carries apocrine glands, and the palm does not. That is why palm sweat is watery and near-odorless, while underarm sweat can develop odor as bacteria act on the apocrine secretion.
Why do palmar eccrine glands respond to nerves rather than heat?
Their nerve supply is wired to sympathetic activity that peaks with alertness and emotion, not with core temperature. That is a feature of how palmar skin developed, and it is why nervous or focused moments dampen the palm before a warm room does.
Sources & further reading
The reputable organizations our editorial team draws on for the anatomy, definitions, and safety guidance behind this page, and where you can read more on each topic.
General educational information about sweating. Not medical advice, and not a substitute for diagnosis or treatment by a qualified healthcare professional.