Dermatologists Reveal the Health Secrets Hidden in Your Skin

Our skin is the body's largest organ, and one of the most complex, containing sweat glands, blood vessels and nerve endings, among other features.

It forms a crucial protective barrier between the external environment and our internal organs. It protects us against pathogens and chemicals, while also serving to regulate our temperature.

It also acts as a sensory organ, stores water and fat, and helps to produce vitamin D when exposed to the sun.

But the skin can also be a window into our overall health, Shari Lipner, an associate professor of clinical dermatology, and director of the Nail Division, at Weill Cornell Medicine, told Newsweek.

How can skin reveal signs of disease?

Anthony Rossi, an American Academy of Dermatology board-certified dermatologist, told Newsweek there are "so many things" that our skin can tell us about about an individual.

Changes to the skin can be an indicator of several medical conditions or underlying diseases, although most skin disorders are not signs of serious illness.

If the skin takes on a yellow appearance or the whites of the eyes become yellow, this is often a sign that the individual has elevated levels of liver enzymes or bilirubin, which can indicate a problem with the hepatobiliary system—the liver, gall bladder and bile ducts—such as jaundice, according to Rossi.

Similarly, if the palms become a deep yellow color or your skin turns yellowish-orange, this may be a sign of excessive beta-carotene ingestion. Excessive consumption of foods that are rich in this substance—such as carrots, squash and sweet potatoes—or beta-carotene supplements, can cause a condition known as carotenemia, which is characterized by these symptoms.

Is itchy skin something to worry about?

While itchy skin is relatively common, in rare cases, it can be a sign of an underlying disease, such as diabetes or lymphoma. Having itchy skin does not necessarily mean you have either of these conditions, and there are causes of this symptom that are far more common, for example, skin conditions like eczema or skin infections.

Seborrheic dermatitis—a common skin condition that mainly affects the scalp causing scaly patches, red skin and dandruff—is more prevalent in patients with Parkinson's disease, according to a 2021 study. The skin condition has also been associated with HIV and appears to be much more prevalent in patients infected with the virus.

Rashes can be a sign of many issues and can be caused by factors as varied as heat, allergic reactions or medications. But in some cases rashes can be a sign of underlying diseases as well. For example, both Lyme diseases and lupus produce distinctive rashes. And secondary syphilis sometimes results in a characteristic rash on the palms, Rossi said.

If you scar poorly or your skin is quite stretchable, this could be symptoms resulting from a group of genetic syndromes known by the name Ehlers-Danlos, according to Rossi.

These rare syndromes are inherited disorders that affect the connective tissues, such as the skin joints and walls of the blood vessels. As well as stretchy, fragile skin, people with this condition may also have overly flexible joints.

Warning signs of heart disease or problems with the blood vessels can also show up on the skin. For example, Lipner said some heart issues may result in purple spots on the digits.

And according to Rossi, if there is inflammation in certain blood vessels, the skin can show signs of palpable purpura, a condition characterized reddish dots that don't blanch when compressed.

Scurvy is a disease caused by vitamin C deficiency, which can result in skin that easily bruises and "corkscrew hairs," Lipner said. Scurvy is a relatively rare today in more affluent countries but is more common in the developing world and is often associated with malnutrition.

What can a person's skin reveal about them?

The skin can reveal a variety of clues about a person's lifestyle and behaviors. A dermatologist can look at how tanned someone is or look for signs of sun damage to gauge how much outdoor exposure that individual has had.

People who smoke will also often notice changes in their skin. Smokers may have discoloration of the skin on their fingers, while dark spots can appear on the face. This habit can also cause the skin to age and wrinkle prematurely, Lipner said.

Smoking has been shown to damage the repair mechanisms in the skin. It also affects fibrous substances known as collagen and elastin, which provide strength, support and elasticity. Smokers tend to to have fewer collagen and elastin fibers, which can lead to the skin becoming slack, hardened and less elastic, according to 2019 study.

The skin may also exhibit giveaways that an individual may not be getting enough sleep.

"Droopy, saggy, dark circles under the eyes can be a clue to fatigue," Steven Daveluy, a dermatologist with the Wayne State University School of Medicine, said in a blog post for the American Academy of Dermatology.

A lack of sufficient hydration may also produce certain visible signs in the skin, according to Daveluy. "One of the signs of dehydration is sunken-looking skin around the eyes," he said. "Dry skin can also indicate dehydration."

Dry and itchy skin is commonly experienced by people, especially in the winter. But this condition can also be caused by constant hand washing or the frequent use of alcohol-based sanitizers, like those that have become ubiquitous during the COVID pandemic.

What should healthy skin look like?

According to Rossi, healthy skin comes in many forms. But there are some general signs that people can look out for. "You want your skin to look well hydrated, not dry or cracked, good elasticity and without spontaneous bruising," he said.

"We all have different skin tones so bruising and rashes look differently on different skin types."

A relatively consistent skin color or even pigmentation all over the skin can be a sign that the organ is healthy, Lipner said.

But some experts note that variations in color are not necessarily always signs of unhealthy skin.

"Healthy skin can vary in color and may have freckles or darker pigmentation around the eye area," consultant dermatologist, Malvina Cunningham, told Skin + Me. "Healthy skin can have lines and wrinkles and may have occasional breakouts."

"Healthy skin may have a few more prominent blood vessels around the nose area or redness over the cheeks. The truth is that healthy skin looks slightly different for different people and at different stages of their lives."

Healthy skin should also look and feel somewhat smooth, although this does not mean it has to be like this all over the body.

"Healthy skin is uneven in texture," Cunningham said. "It feels smoother and more delicate around the eye area but may be tougher over the cheeks and forehead. Normal, healthy skin may feel dry over the cheeks and oily in the T-zone or alternatively, dry or oily all over."