This is what your nails tell you about your health

Fungal infection or suspected lung disease? Look carefully at your fingernails. These deformations and discolorations can indicate illness.

The eyes are the gateway to the soul, while the fingernails are a mirror of our health. But do you really have to drink more milk if you have white spots on your nails, because that’s supposed to be a sign of calcium deficiency? And are blue fingernails an indication that you have too little oxygen in your blood? Our expert, the dermatologist Dr. med. Ute Siemann-Harms, senior physician at UKE-Hamburg, explains the myths of nail science. It shows what color, structure and shape of the fingernails can actually reveal about your mental and physical health.  

What do healthy fingernails look like?

This is what healthy fingernails should look like: a smooth surface without dents, with a subtle sheen, a light pink color and elastic. If this description doesn’t fit your fingernails, you can use these 6 steps to change it for nicer nails . If you don’t have the so-called “nail moon” under every fingernail, which looks like a milky-white crescent moon and goes directly from our nail bed, there is nothing to worry about. Everyone is different. The nail moon is often no longer recognizable on the little finger.

The fingernail grows on average about 0.5 to 1.2 millimeters per week. In older people, nails grow more slowly. There are also seasonal fluctuations, the nails grow a little slower in winter and faster in summer. Why? Simple answer: The UV light from the sun promotes the production of vitamin D in the body. This in turn stimulates nail growth.

What are 3 the most common fingernail disorders?

If the fingernail is directly affected, i.e. does not indicate any other indirect disease, then it is often one of the following diseases:

1. Eczema nail : If patients suffer from eczema (e.g. neurodermatitis), this can also show on the skin around the fingernail. Consequence: The nail no longer grows normally. It becomes porous, the surface is rubbed and the nail warps. Often the nail bed is already affected.  
2. Fungal diseases : The fingernail becomes discolored, cracked, brittle and can either peel or thicken. Anyone who suffers from fingernail fungus should urgently examine their toenails: the origin can often be found down there, namely in the form of athlete’s foot. If this is not recognized in time, the much worse nail fungus (onychomycosis) follows. When drying off their feet or doing a pedicure, many patients become infected with the infection. Nail fungus can be treated , but it is extremely annoying.
3. Psoriasis or nail psoriasis : A typical feature is the so-called spot nail. The nail is covered with tiny dents (pits) that are either isolated or in groups. Another characteristic: brownish-yellow spots (oil spots) under the nail. In the case of nailworm, there is an inflammation in which the nail cover slowly separates from the nail bed. Not necessarily, but in many cases there is also a general lichen, for example on the elbow.

Brittle, grooves, dents in fingernails: what do fingernails say about diseases?

• Dents and dimples : They tend to occur with all kinds of eczema (such as neurodermatitis). Individual dents, on the other hand, can also be the result of everyday injuries or bruises to the nail bed. 
• Longitudinal grooves : no stress. These are normal signs of age from 35 years.  
• Lateral grooves : One often finds the note “acute malnutrition” on Internet sites. But, at least in Western Europe, these are rare, according to our expert. But: If  a  horizontal groove runs across  all  fingernails at the same height, it can be assumed that the patient has suffered a severe infection. However, this is very likely already in the past. Because: fingernails only grow 0.2-0.3 centimeters per month. Many common infections have already subsided during this period before the patient recognizes it on his fingernails.  
• Brittle nails : They can be traced back to depleted, porous nail plates, for example from frequent hand washing or dish washing. Only if nails keep breaking or splintering over a period of months can the thyroid gland actually be underactive. 
• Horizontal splitting : The nail consists of two layers, if these are divided into 2 levels, this could be a sign of iron deficiency and a thyroid disease, according to our expert.

Discoloration of fingernails: what do yellow, white, green fingernails mean? 

• Pale fingernails : acute anemia? The all-clear: “Then the patient would also have to be ghostly pale in the face,” says our expert. Anemia is more likely to be recognized by the eyes and face than by the fingernails. But: tall and slim people tend to have pale fingernails and cold hands and feet. Background: The circulatory system has to go further ways in order to pump the blood to the furthest corners of the body. But that’s all normal and nothing to worry about.        
• White spots : Leukonychia punctata! In other words: harmless. The rounded white dots or spots are air pockets that arise and grow out during normal growth. So it’s not a calcium deficiency, just a minor manufacturing error during growth. If you are disappointed with the diagnosis, you are welcome to drink a glass of milk.    
• Green fingernails  (chloronychia): They could be infected with the moist germ Pseudomonas aeruginosa. This is not a monster from the swamp, but unfortunately your nails look similar after the attack: They take on a mossy-green-dark color. The bacterial pathogen likes to romp around in damp areas, such as sinks or in sponges. Risk group: if your nails are porous or damaged. So anyone who comes into contact with water a lot at work, frequently applies disinfectants, or is constantly condemned to wash the dishes privately, should take care and take good care of their nails.   
• Blue fingernails : They could be an indicator of heart or lung disease. Provided the patient is poorly supplied with oxygen. However, the person would first notice a lack of oxygen through other symptoms, such as shortness of breath.      
• Yellow fingernails : It could indicate a fungal infection. But: If the nails also grow thickened, hardened and crooked out of the nail bed, you could   suffer from yellow nail syndrome : This can occur with various underlying diseases, often there is a lung disease.  
• Light brown nails : suspected nail fungus. Off to the doctor!   
• Dark brown to black spots : You should make a distinction here: If the spots appear acutely but slowly grow out of the nail, it could be that you have trapped yourself somewhere or hit your finger. If the stain does not grow out, it can either be a pigment mark or black skin cancer (melanoma). If you don’t remember a painful situation that could have resulted in a bruise, make an appointment with the doctor. Important: Document the development of the stain, advises our expert. Take a cell phone photo every week until the appointment. Then the dermatologist can make a better diagnosis. Because skin cancer in the nail is unfortunately not that rare. 

Conclusion: If there is any discoloration, go to the doctor

If your fingernails are discolored, you should see a dermatologist ( the color of the toenails can also indicate diseases ). Bacteria in the nails and skin could be the cause here. A black spot can – if there are no bruises or other accidents – be an indication of skin cancer. On the other hand, the shape or color of the nails rarely say anything about a nutritional deficiency. Only if the nails split horizontally would this be an indication of iron deficiency. However, this is more likely to be attributed to a thyroid disease than to a direct food deficit.