Definition and Overview

Nail problems, though seemingly minor, are actually important indicators of a variety of health problems, ranging from infection to serious diseases. Although the nails are very small and may seem insignificant, the truth is that they play an important role in the body. They are responsible for protecting and supporting the fingertips and the tips of the toes. Other than that, they also tend to act as health indicators. Indeed, a lot of medical conditions have an effect on the nails, which is why fingernail or toenail abnormalities should not be ignored.

Cause of Condition

Different nail problems can spring from a wide variety of possible causes, such as:

  • Fungal or bacterial infection
  • Poor nutrition, e.g. lack of iron leading to anemia or excessive iron leading to haemochromatosis
  • Poor circulation
  • Pregnancy
  • Chemotherapy
  • Medicinal allergies, more commonly occurring after the intake of certain antibiotics

Some nail problems are also caused by underlying issues that affect certain parts of the body; these possible causes include:

  • Skin conditions, such as psoriasis, lichen planus, eczema, and lymphoedema
  • Thyroid issues, such as hyperactive thyroid or underactive thyroid that causes it to produce too many or too little hormones, respectively
  • Lung conditions, such as bronchiectasis or tuberculosis
  • Sinus problems, such as inflamed sinus lining
  • Liver problems, which causes jaundice or the yellowing of the skin and nails

    Nail problems are also known symptoms of specific diseases, including:

  • Sarcoidosis, a condition that causes cells to abnormally form in clusters in various organs of the body

  • Amyloidosis, a condition characterized by the abnormal protein accumulation in the organs of the body
  • Raynaud’s disease, a condition wherein the blood supply to the fingers and toes is constricted
  • Lupus erythematosus, an autoimmune condition wherein the body attacks its own cells and tissues
  • Polycythaemia, a condition wherein a person’s blood is thicker than normal
  • Reactive arthritis, in which the body’s immune system reacts to an infection and affects various parts of the body such as the nails, joints, and muscles

Several negative lifestyle factors or habits that may affect the nails are:

  • Excessive or frequent application of nail polish or varnish
  • Ill-fitting shoes, which inhibit the nail from growing properly
  • Smoking

Key Symptoms

Nail problems manifest in many forms, and the specific type of problem is often very helpful in determining the underlying cause. The many different types of nail problems include:

  • Brittle nails – Brittle nails that break easily may be a sign that the person’s hands are exposed to chemicals for prolonged periods.

  • Discoloration – Characterized by any abnormal color in the nail, discoloration may be a sign of an infection, and the color is also a valuable clue as to what kind of infection is present. For example, a green-black color is often the most telling sign of a bacterial infection. In addition, discoloration may also be a sign of other health issues, both minor and serious. While grey-colored nails are usually side effects of an antimalarial or minocycline medication, a brown color covering the upper half of a nail suggests a problem, or potential failure of the kidneys; in fact, this symptom affects up to 40 percent of kidney failure patients.

  • White nails - Whitening of the nails points to a possible liver cirrhosis or iron-deficiency anemia.

  • Infected nail bed or nail fold – Accompanied by pain, inflammation, and the presence of pus, an infected nail bed or nail fold may be caused by a bacterial infection, an injury, or an underlying medical problem, possibly diabetes or even HIV. If the infection does not seem to respond to treatment or tend to recur, it is best to undergo health screening to determine the cause of the problem.

  • Loosening of the nails – Loose nails may be a result of injury to the nail, but they can also indicate the presence of fungal infection, psoriasis, fingernail warts, thyroid problems, sarcoidosis, Raynaud’s disease, and amyloidosis, among other diseases.

  • Thick nails with overgrowth – This is an easy symptom to detect as the overgrowth is usually so thick that it’s hard to cut the nails using a regular nail cutter. This may be caused by a nail disorder called onychogryphosis, but is more popularly known as ram’s horn nails due to the horn-like appearance that the nails take on. It is known to be caused by long-term pressure on the nails.

  • Indented nails or koilonychia – Characterized by a spoon-like appearance, indentations on the surface of the nail may be signs of serious underlying diseases.

  • Pits on the nail surface – Pits and dents are telltale signs of skin conditions such as psoriasis and eczema. In fact, as many as 50% of psoriasis sufferers have pitted nails.

  • Horizontal grooves across the nails – These develop from the base of the nails as a result of a disruption during the nail growth stage; these disruptions are commonly caused by cold temperature, chemotherapy, or Raynaud’s disease. These are considered as early signs of illness that develop around the same time the illness begins, but patients often only notice them months after when the grooves have moved up enough to become noticeable.

  • Dark vertical streaks – More common among adults with darker skin, these are called linear melanonychia and may be a normal effect of darker pigmentation in the body or a symptom of skin cancer affecting the nail bed. The latter, however, usually affects only one nail, making it easy to distinguish between the two causes of these dark streaks running from the top of the nail to the bottom.

  • Curved or clubbed nails – The most noticeable of all types of nail problems, curved or clubbed nails have a bulbous appearance. It is generally known to be caused by an increase in blood flow to the ends of the fingers. The problem with this particular symptom is that it can either be completely harmless (if it is passed on within families) or a sign of a serious, long-term disease. This nail problem has been associated with stomach cancer, bowel cancer, liver cirrhosis, lung cancer, heart disease (such as endocarditis), and inflammatory bowel disease.

Who to See and Types of Treatment Available

Any sudden changes, as well as chronic or recurrent nail problems, should be brought to the attention of either a general physician or a dermatologist. Patients can also go to a specialist called a podiatrist.

There are many possible ways to treat and manage nail problems that are short-term, long-term, or recurrent. The appropriate treatment method depends on the specific cause of the problem.

Fungal nail infections can be treated with antifungal medication, while underactive and overactive thyroid glands that have an effect on the nails can be treated with hormone therapy to regulate the proper production of hormones and avoid nail problems from developing. Bacterial infections, on the other hand, should be treated using antibacterial eye drops and a hand soak containing an antiseptic solution. Once the underlying causes are identified and treated, the patient’s nail problems will also disappear.

Proper nail care can also help prevent nail problems from occurring. Some helpful measures include taking vitamin B7 or biotin supplements, wearing work gloves to protect the hands and fingers when doing wet activities, such as washing the dishes or laundry, and lastly, applying topical hand and nail moisturizing cream on a regular basis.


  • Sperling LC, Sinclair RD, El Shabrawi-Caelen L. Alopecias. In: Bolognia JL, Jorizzo JL, Schaffer JV, eds. Dermatology. 3rd ed. Philadelphia, PA: Elsevier Saunders; 2012:chap 69.
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