Health conditions that show up in your nails

Health conditions that show up in your nails

What your nails can tell you about your health

Nails are exposed to all sorts of things. They can experience injury or even show us signs of something that may be amiss internally. Many health conditions can influence the condition of our nails, showing clear indicators that some or other function is not quite right. When it comes to nail changes as a result of disease, however, such indications are not usually the very first sign.

Nevertheless, there are some particularly distinctive changes that can occur within the nails that may be indicative of changes within the body, ranging from minor to more serious health issues, which you can either resolve on your own or have appropriately diagnosed and treated. Changes can involve the colour, shape or even texture of the nails – some of which are completely harmless and not indications of disease, while others can be helpful in diagnosing a medical condition requiring treatment.

We've listed some nail problems and what they could mean below:

Nail problem: Discolouration of the nail

1. Yellow

Close-up of yellow discolouration of the fingernails.
Characteristics & appearance

The healthiest colour for nails to be is pinkish with a white lunula. Sometimes when yellow discolouration occurs, the nail plate thickens, and growth tends to slow down. This is often referred to as yellow nail syndrome. The cuticle may also detach (a little) from the nail bed.

What could this problem indicate?
  • Natural aging process
  • Staining of nail lacquers (or nail polish) and acrylic applications
  • Staining from nicotine (cigarette smoking)
  • Staining from hair colouring chemicals and dyes
  • Injury to the nail bed
  • Infection – fungal or bacterial (nail beds may retract and thicken or crumble as infection worsens or goes untreated)
  • Side-effect from certain medications like antibiotics, anti-malarial drugs and some used for chemotherapy treatment
  • Melanoma (a cancerous / malignant condition)
  • Yellow nail syndrome can also sometimes be an indicator of chronic bronchitis and other respiratory diseases, or lymphedema (a condition which results in swelling)
  • Discolouration can also occur in people with lung disease, psoriasis, diabetes or thyroid dysfunction.
Should you seek a medical consultation?

Discolouration due to aging or staining isn’t normally problematic. Giving the nails a break from nail applications can help them to recover and return to their normal, healthy colour.

Injury, side-effects, medical condition or infection causes which result in considerable discomfort should be assessed by a medical doctor. Aside from yellow discolouration, other signs of a fungal infection include nails which thicken and begin to crumble.

Bacterial infections typically begin in the folds of the nail (skin – known as paronychia), resulting in inflammation and often the formation of pus (which is usually a yellow-green colour). Pain, swelling and redness can also occur around the cuticle area.

Infections and melanoma will require medical treatment as soon as possible.

Treatment for infections may involve oral medications (antifungals and antibiotics), use of medicated barrier creams and lotions, and maintaining dryness of the affected areas as much as possible to help prevent spread of infection and inflammation.

The treatment of fungal infections may also involve photodynamic or laser therapy or an excision of the affected nail plate (nail avulsion / surgical removal).

2. White spots

Close-up of white spots on a thumbnail.
Characteristics & appearance

Many believe that the development of a white patch or spot on the nail is an indication of a calcium deficiency – more often than not, this isn’t actually the case. (4)

White discolouration is referred to as leukonychia.

What could this problem indicate?
  • It is more likely that a small spot has developed due to a minor contact injury.
Should you seek a medical consultation?

Small spots are not normally something significant to worry about and will generally fade or grow out on their own. In this instance, no medical attention is necessary. Should a spot not fade or grow out, it could indicate a fungal infection. If other symptoms are present a medical consult may be needed.

3. Pale / White

Close-up of white fingernail discolouration
Characteristics & appearance

Extensive white discolouration on one or more nails can indicate a potentially serious medical condition.

Nails that develop white discolouration virtually all over the plate with dark rims can indicate severe liver dysfunction. Discolouration of the fingers or toes may accompany this nail change – a yellow hue of the surrounding skin may be indicative of jaundice.

If the nails begin to lighten (i.e. will have a white discolouration) from the cuticle to the tip and develop a pink, red or brown band of discolouration near the tip, this condition may be referred to as Lindsay half and half nails.

What could this problem indicate?
  • Anaemia
  • Malnutrition
  • Liver disease
  • Hepatitis
  • Congestive heart failure
  • Lindsay half and half nails may indicate problems with internal swelling or anaemia, and renal dysfunction / disease
Should you seek a medical consultation?

Medical attention is required as soon as possible for appropriate testing and diagnosis.

4. White with a pink band / strip

Pink bands or stripes in nails
Characteristics & appearance

White discolouration that is accompanied by a narrow pinkish strip or band is known as Terry’s nails. Reduced vascular supply to the nail bed is thought to cause the nail change

What could this problem indicate?
  • Natural aging process
  • Liver disease
  • Kidney failure
  • Diabetes
  • Congestive heart failure
  • Hyperthyroidism (overactive thyroid gland)
Should you seek a medical consultation?

If no other signs or symptoms develop, Terry’s nails may be part of a harmless aging process. Accompanied by other problems and discomforts, this change must be evaluated by a medical doctor as soon as possible.

5. Blue

Close-up of blue discolouration of the toes and toenails.
Characteristics & appearance

Bluish discolouration may occur due to the cold but is most often as a result of a lack of oxygen reaching the nail structure.

What could this problem indicate?
  • Lung dysfunction (e.g. emphysema)
  • Heart dysfunction
Should you seek a medical consultation?

Chronic blue nails should always be evaluated by a medical doctor as soon as possible to either diagnose or rule out a potentially serious condition.

Nail problem: Lifted nail plate

Close-up of a lifted nail plate (fingernails)
Characteristics & appearance

The nail loosens / separates from the nail bed (lifts). This is known as onycholysis. The lifted portion is no longer translucent and becomes white or opaque, sometimes with a tinge of yellow or green discolouration.

What could this problem indicate?
  • Excessive cleaning under the nails (leading to injury)
  • Use of nail polish or lacquer containing chemical compounds like formalin which tend to harden the nails
  • Nail adhesive products
  • Removing artificial nail products in a harsh or rough manner
  • Fungal infection (nail plate separation may be accompanied by nail thickening and crumbling, discolouration or discharge)
  • Psoriasis
  • Thyroid dysfunction
Should you seek a medical consultation?

In the case of conditions affecting the skin, like a fungal infection or psoriasis, lifting of the nail plate will likely be one of several physical indications requiring medical diagnosis. In this instance, a consultation should be arranged as soon as possible.

A medical consultation is also necessary for other physical conditions like problematic thyroid gland function.

Nail problem: Thickened nails

Close-up of a thickened toenail.
Characteristics & appearance

Thickening of the nail plate more commonly affects the toenails than the fingernails.

What could this problem indicate?
  • Natural aging process
  • General neglect
  • Poor circulation
  • Wearing of poorly-fitted shoes
  • Problems with gait (i.e. pattern of walking)
  • Injury
  • Fungal infection
  • Arthritis
  • Psoriasis
Should you seek a medical consultation?

Discomfort, pain or other accompanying symptoms should be evaluated by a medical doctor, especially if the underlying cause may be arthritis, psoriasis or a fungal infection.

Nail problem: Nails with ridges

Close-up of vertical ridges and white spots on thumbnails.
Characteristics & appearance

The formation of ridges on the nail plate can run vertically or horizontally (length or width wise). Ridges which affect more than one nail at a time are associated more so with illnesses than an injury.

Horizontal ridges are known as Beau’s lines or Mees’ lines. The latter are typically characterised by horizontal discolorations on the nail plate.

What could this problem indicate?
  • Associated with natural aging changes (applicable to vertical ridges)
  • Injury or trauma to the nail root or nail bed
  • Excessive cuticle “grooming”
  • Circulatory problems
  • Zinc deficiency
  • Deficiencies in magnesium or vitamin B12
  • Related to fever-causing illnesses (e.g. scarlet fever, measles, mumps or pneumonia
  • Rheumatoid arthritis
  • Eczema
  • Peripheral vascular disease
  • Lichen planus (inflammatory condition)
  • Psoriasis
  • Diabetes (uncontrolled)
  • Mees’ lines can be caused by arsenic or carbon monoxide poisoning, malaria, leprosy or Hodgkin’s disease
  • Side-effect of recent chemotherapy treatment
Should you seek a medical consultation?

Vertical ridges which develop as part of the aging process are normally considered harmless (almost like ‘nail wrinkles’), even if they become more prominent over time.

Nail problem: Split, brittle, cracked and dry nails

Close-up of a split or broken toenail.
Characteristics & appearance

The nail plate splits from the nail bed (partially or completely). This is sometimes known as onychorrhexis or onychoschizia. The split portion can also begin to grow away from the nail bed. Dryness of the nail can result in splitting and cracking.

What could this problem indicate?
  • Excessive use of nail polish / lacquer and removal agents
  • Hands or feet that are wet for long periods and exposed to soap and other washing detergents and cleaning products
  • Residing in a low-humidity environment
  • Repetitive mild trauma, such as using the fingernail as a ‘tool’ or habitual picking between the teeth
  • With aging changes, dryness can also occur during the senior years
  • Nutrient deficiencies (vitamin A, C and biotin)
  • Thyroid dysfunction - hypothyroidism (underactive thyroid)
  • Fungal infection
Should you seek a medical consultation?

Non-condition causes can be alleviated with the use of highly moisturising lotions. Like the skin, nails are quite absorbent – regular moisturising can also help to prevent dryness over time, reducing the risk of cracking and splitting.

Infections and other underlying medical conditions must be diagnosed and treated by a medical doctor as soon as possible.

Nail problem: Deformations (unusual shapes)

Close-up of nail deformation affecting the toenail.
Characteristics & appearance

Nails can take on an unusual or unnatural shape. One such shape deformation is known as “spoon nails” (koilonychia) – the nail plate softens and becomes concave, taking on a scooped-out appearance (i.e. forming a depression). The ‘scoop’ may be big enough to hold a little liquid.

What could this problem indicate?
  • Injury or trauma to the nail plate and nail bed can result in nail thickening and ridging. This can result in abnormal growth and normal shape distortion.
  • Iron deficiency and iron deficiency anaemia (nails may also become pale in colour)
  • Hemochromatosis (excess iron in the body that is absorbed mostly from ingested food)
  • Heart disease
  • Hypothyroidism
Should you seek a medical consultation?

The development of unusual nail shapes must be assessed by a medical doctor. “Spoon nails” are most often associated with iron irregularities which can be managed with medications and supplements.

Those who experience irregular growth of the nails may also benefit from regular trimming and shaping – enlisting the services of a podiatrist may be useful in keeping irregularly shaped nails groomed.

Nail problem: Ingrown nails

Close-up of an ingrown toenail.
Characteristics & appearance

The large toe is particularly prone to ingrown nails, which can be quite painful. (5)

What could this problem indicate?
  • Nail injury (e.g. stubbing a toe)
  • A naturally sharp curving nail – nails which grow sharply into the sides, digging into the adjacent skin.
  • Trimming nails incorrectly (e.g. rounded edges)
  • Wearing shoes that are too tight and press onto the toes
Should you seek a medical consultation?

If the ingrown nail is very painful, a podiatrist will be able to assist. If severe, the ingrown section of the nail can be removed while under light sedation (local anaesthetic) to help alleviate pain during the short procedure.

Nail problem: Bitten nails

Close-up of bitten fingernails.
Characteristics & appearance

Biting of the nails is predominantly associated with habit. Such habits are sometimes linked with anxiety related medical conditions. Individuals with a biting habit are sometimes prone to picking at the nails, as well as the skin fold surrounding the nail.  

Nail biting is reasonably common during childhood, which typically peaks during teenage years. For some the habit may resolve on its own (either gradually or abruptly) as a person enters adulthood. For others, the habit may continue, often as a result of another underlying issue requiring medical intervention.

What could this problem indicate?
  • Habitual behaviour (sometimes stimulated by triggers such as boredom)
  • Persistent anxiety
  • Obsessive-compulsive disorder
Should you seek a medical consultation?

Those with nail biting and picking habits which are associated with anxious behaviour can benefit from medical intervention. Medications can be prescribed for diagnosed anxiety-associated conditions, which can in turn help to alleviate the behavioural habit.

A habit that does not necessarily present any other clinical symptoms of a disorder can sometimes be addressed with the use of nail varnishes or polishes containing bitter compounds that are off-putting to a ‘biter’. Habitual biters can benefit from regular manicures – keeping nails well-trimmed and short.

Nail biting and picking can make a person vulnerable to skin infections like paronychia – wherein microorganisms like bacteria can enter the injured skin areas more easily causing infection. Signs of infection can include redness, swelling and discharge (pus) around the nail.

Nail problem: Pitting

 Nail Pitting - dents in nails
Characteristics & appearance

Depressions or dents in the nails are generally referred to as ‘pitting’. More than one dent in the nail is most often associated with the scaly skin condition, psoriasis. Rippling of the nail may accompany dents, as well as some discolouration – often a reddish-brown hue.

What could this problem indicate?
  • Psoriasis
  • Reiter’s syndrome (also known as reactive arthritis – inflammatory disorder)
  • Alopecia areata
Should you seek a medical consultation?

It is best not to ignore the development of dents in the nails. A medical professional will assess all symptoms along with pitted nails and test as appropriate in order to make a diagnosis. Whatever the underlying cause, applicable treatment procedures can help to provide control of this symptom.

Nail problem: Clubbing

Close-up of fingers / fingernails affected by clubbing.
Characteristics & appearance

The tips of the fingers and toes can become swollen (enlarged). The nail plates then also enlarge and begin to curve downward around the swollen fingers or toes. This curve may be measured at around 180 degrees or more. (6) This rounding process is normally gradual, taking place over the course of a few years.

What could this problem indicate?
  • Low blood oxygen levels
  • Lung dysfunction
  • Inflammatory bowel disease
  • Liver disease
  • Cardiovascular disease
  • AIDS
Should you seek a medical consultation?

A medical diagnosis is required in order for appropriate treatment to be implemented for all applicable symptoms, including that of clubbing.

Nail problem: Lunula abnormalities

Close-up of thumbnail without a normal lunula.
Characteristics & appearance

Discolouration, shape changes or a total lack of presence of the lunula (the white area at the base of the fingernail) may sometimes occur, for various reasons.

What could this problem indicate?
  • A lunula which takes on the shape of a pyramid may indicate injury to the nail, which can include excessive manicuring.
  • Pale blue discolouration may signal diabetes
  • Pink / reddish discolouration may indicate cardiovascular problems or collagen vascular disease.
  • A lack of a lunula can sometimes occur as part of the aging process – if no other abnormalities develop, it may not be something to worry about.
  • A lack of a lunula with other nail abnormalities may indicate problems with malnutrition or anaemia.
Should you seek a medical consultation?

Discolouration of the crescent-shaped structure should be assessed by a medical doctor to either diagnose or rule out potentially problematic or serious conditions. Appropriate testing will be determined according to the overall symptoms a patient presents with.

A lack of a lunula that is accompanied by any other types of nail changes should be evaluated by a medical professional.

Nail problem: Puffy / inflamed nail fold

Close-up of young child's hand and fingernail affected by Paronychia.
Characteristics & appearance

The skin surrounding the nail fold can become inflamed, resulting in swelling, redness and discomfort / pain.

What could this problem indicate?
  • Connective tissue disorders
  • Lupus
  • Infection
Should you seek a medical consultation?

A medical evaluation may be helpful in either diagnosing an applicable condition, managing this symptom or ruling out other clinical possibilities. It is advisable to seek medical consultation in order to resolve the issue.

Nail problem: Dark stripes / a growth

Close-up of toenail affected by a dark streak / stripe (discolouration)
Characteristics & appearance

The development of lines, stripes or streaks that are a dark colour (brown, sometimes black) can often be painful. These can sometimes be accompanied by the development of a skin growth / nodule nearby to or beneath the nail plate. Growths may also be a dark colour and painful.

Streaks / lines may develop gradually, affecting one nail at a time (generally).

What could this problem indicate?
  • Melanoma (skin cancer)
Should you seek a medical consultation?

A prompt medical consultation is necessary. Streaks and growths which develop on (and close to) the nail are considered serious and must be evaluated by a medical doctor as soon as detected.

Malignant cells which develop beneath the nail are likely to be diagnosed as subungual melanoma (following a punch biopsy) – often accompanied by other nail changes including nail lifting, cracking or splitting of the nail plate and a darkening of the skin alongside the nail. Diagnosis and treatment are necessary as malignancy can spread.


4. 11 February 2005. Worried About White Spots On Fingernails?: [Accessed 11.09.2018]

5. National Center for Biotechnology Information28 June 2018. Ingrown Toenail: Overview: [Accessed 11.09.2018]

6. National Center for Biotechnology Information. 1990. Clinical Methods: The History, Physical, and Laboratory Examinations. 3rd edition. Chapter 44 - Clubbing:[Accessed 11.09.2018]

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