What can cause sweat to appear yellow?

Medical News Today

a day ago

Different factors can cause a person's sweat to change color. Typically, if a person's sweat appears yellow, it may be due to a substance in the sweat or the sweat reacting with a substance on the skin.
Sweat is a bodily fluid that the sweat glands in the skin excrete. The primary function of sweat is to help regulate body temperature by cooling the skin as it evaporates. This is why people often perspire in hot weather or when exercising.
Sweat mostly consists of water, but also contains other substances. In many cases, sweat may be colorless. However, if there is a high level of certain substances in sweat or on the skin, then sweat may appear different colors, such as yellow. skynesher/Getty Images
A few different factors can cause a person's sweat to appear yellow or a different color. Typically, this occurs when a pigment is present in sweat and causes discoloration, or something interacts with sweat on the skin and causes it to appear a different color.
For example, lipofuscin is a yellow-brown pigment that the body naturally produces. It is the byproduct of the oxidation process of unsaturated fatty acids. When a person has a higher concentration of lipofuscin in their sweat glands, or lipofuscin that is in a higher state of oxidation, it can cause sweat to appear a different color.
In other cases, ingesting water-soluble dyes, heavy metals, and certain chemicals or having these substances present on the skin can cause sweat to appear yellow.
Possible causes of yellow sweat may include:
The apocrine sweat glands are present in areas of the body that possess many hair follicles, such as the armpit or groin. They produce a thicker sweat, which can be responsible for the smell that people associate with sweat. The eccrine glands are present all over the body and secrete a thin, watery sweat that helps to cool the skin.
Certain situations can stimulate apocrine chromhidrosis due to higher levels of lipofuscin. This can include skin friction, hot showers, or certain stimuli such as anxiety or sexual arousal.
Eccrine chromhidrosis may occur after a person ingests water-soluble dyes, which are common in medications, heavy metals, such as copper, or certain food colorings. For example, some medications may have a coating that contains tartrazine, which is a yellow dye.
Other causes of eccrine chromhidrosis may include underlying health conditions. For example, hyperbilirubinemia describes high levels of the yellow pigment bilirubin in the blood. This can result in jaundice and yellow sweat.
Pseudochromhidrosis is more common than chromhidrosis. It instead occurs after secreting sweat as it comes into contact with dyes, chemicals, or bacteria that produce pigments.
For example, a person may notice yellow sweat around the armpits on pale clothing after using antiperspirants that contain aluminium.
Hematohidrosis, or blood sweat, describes a rare condition where a person's sweat contains blood. Although the exact cause is unknown, it likely occurs due to tiny blood vessels rupturing near the sweat glands. However, this is unlikely to produce yellow sweat and instead cause sweat that is red in appearance.
Lipofuscin is usually a yellow-brown pigment . Depending on the levels and state of lipofuscin in the apocrine sweat glands, it can cause sweat to appear as different colors. According to the International Hyperhidrosis Society, lipofuscin can cause sweat to be the following colors: yellow
green
blue
brown
black
Yellow sweat may appear in different areas of the body depending on the underlying cause.
For example, apocrine chromhidrosis will present with yellow sweat in areas where the apocrine sweat glands are present. This includes the armpits, areolas, and groin.
Eccrine chromhidrosis can affect skin anywhere on the body, but is more likely to appear in areas with more eccrine glands, such as the palms of the hands and soles of the feet. Pseudochromhidrosis can also affect any part of the skin, but is more common on the face, neck, and palms.
Treatment for yellow sweat will also depend on the underlying cause.
For eccrine chromhidrosis, a person will need to avoid the causative agent or treat the underlying cause of yellow sweat. With pseudochromhidrosis, a person can either avoid the causative dye or chemical or use an antiseptic soap or antibiotics to treat the bacteria causing discoloration of their sweat.
Sweat may appear yellow if a person has high levels of certain substances in their sweat, such as lipofuscin or bilirubin. In other cases, sweat may turn yellow if it reacts with certain dyes or chemicals, such as antiperspirants, or if they have bacteria that produce pigments on their skin.
Treatment for yellow sweat will depend on the underlying cause. Options may include treatments to reduce sweating, antiseptic soaps, or avoiding the causative agent. Medical News Today has strict sourcing guidelines and relies on peer-reviewed studies, academic research institutions, and medical journals and associations. We only use quality, credible sources to ensure content accuracy and integrity. You can learn more about how we ensure our content is accurate and current by reading our editorial policy.