Fingernail or
toenail abnormalities can tell you a lot about your health. They are often a
sign of a fungal nail infection or injury, but can sometimes indicate
a more serious underlying condition. You must see your doctor/ GP if your nails have changed in colour,
texture, shape or thickness and you don't know why (for example, you
haven't injured your nails or been biting them).
Below are the most likely reasons for
the following nail problems:
- brittle or crumbly nails
- discoloured nails
- white nails
- thickened, overgrown nails
- loose nails
- indented spoon-shaped nails
- pitting or dents on the nails
- grooves going across the width of the nails
- unusually curved fingertips and nails
- white lines running across the nails
- dark stripes running down the nail
- red or brown little streaks under the nails
- a destroyed nail
- infected nail fold (painful, red
and swollen skin next to the nail).
Brittle or crumbly nails
Brittle nails are often just a sign of ageing or
long-term exposure to water or chemicals such as detergents and nail polish. Wearing gloves will help protect your nails while
doing work where your hands are exposed to water. Regularly applying
moisturising cream to your fingers and nails will also help protect them. Sometimes, brittle or crumbly nails can be caused
by:
- a fungal nail infection – this is
often the cause of crumbly toenails and can be cleared by taking a course
of antifungal tablets
- a
skin condition called lichen planus – this can just
affect the nails
- an underactive thyroid or overactive thyroid – where the
thyroid gland either doesn't produce enough hormones or produces too many
- nail psoriasis – a long-term skin
condition that can cause the nails to become crumbly.
Reactive arthritis is a less common
cause of crumbly nails. It's an unusual reaction of the immune system affecting
the joints, muscles and other parts of the body following an infection. If you
have a combination of symptoms affecting different parts of your body,
your GP might consider this condition.
Discoloured nails
The most common causes of a yellow
nail are fungal nail infections or nail psoriasis. Yellow nails can also be caused by any of the
following:
- frequent
application of nail varnish
- lymphoedema – a long-term
condition that causes swelling of the skin
- permanent
damage to your airways caused by bronchiectasis – a long-term lung
condition
- sinusitis – inflammation of the
lining of the sinuses
- inflammation
of the thyroid gland, found in the neck
- tuberculosis (TB) –
a bacterial infection affecting the lungs
- jaundice (yellowing of the
skin) – caused by liver disease
- some
medications, such as mepacrine or carotene
- chronic paronychia – infection of
the nail fold.
Green-black nails can be caused by overgrowth of
bacteria called pseudomonas, particularly under loose nails. It can be treated
by applying antibiotic eye drops underneath the nails or soaking the affected
nails in an antiseptic solution or vinegar. Grey nails can be caused by medications such as antimalarials or minocycline. Brown nails can sometimes be caused by thyroid
disease, pregnancy, malnutrition and frequent use of nail
varnish.
Red or
yellow drop under the nail
If the discolouration looks like a drop of oil
under the nail or is the colour of salmon, you may have psoriasis of the nails.
Half
white, half brown nails
Fingernails that are half white and half brown
(brown near the tips) can be a sign of kidney failure, where the kidneys stop
working properly. The link isn't fully understood, but one theory is
that kidney failure causes chemical changes in the blood that encourage melanin
(a skin pigment) to be released into the nail bed. It's also possible that
kidney failure causes an increase in the number of tiny blood vessels in the
nail bed.
It is estimated up to 40% of people with kidney
failure have "half-and-half" fingernails. They also sometimes occur
in people with AIDS and those who've had chemotherapy.
White nails
If most of the nail has turned white and it isn't
because it has become detached from the nail bed, it's likely to be either a fungal
nail infection or a sign of decreased blood supply to the nail bed, which
causes something known as "Terry's nails". Terry's nails are typically white with
reddened or dark tips and can be a sign of a wide range of medical
conditions, including:
- liver cirrhosis (scarring and damage to
the liver) – about 80% of people with cirrhosis have Terry's nails
- liver,
kidney or heart failure
- diabetes
- iron-deficiency anaemia – where
a lack of iron in the body leads to a reduction in the number of red blood
cells
- chemotherapy
- an overactive thyroid – where
the thyroid gland produces too many hormones
- malnutrition.
Thickened, overgrown nails
A common cause of thickened nails is
a fungal nail infection. This can also cause
them to discolour and become crumbly. Other possible causes of thickened or overgrown
nails are:
- psoriasis – a long-term condition
that tends to also cause red, flaky patches of skin
- long-term pressure
from shoes that are either too small or too narrow over the toes
- reactive arthritis – where the
immune system attacks the joints, muscles and other parts of the body
following an infection.
Severely
overgrown horn-like nails
Sometimes, the toenails become so overgrown and
thickened that they resemble claws and are almost impossible to cut with
conventional nail clippers. This nail disorder, known as onychogryphosis
("ram's horn nails"), is seen in older people or as a response to
long-term pressure on the nails. Regular chiropody can help, but sometimes the
nails need to be removed by a podiatrist or doctor.
Loose nails
It's normal for a toenail to come loose and fall
off after an injury to the toe. Another common cause of a loose nail is
over-manicuring the nails and cleaning underneath them with a sharp object. Less commonly, a loose nail may be a sign of one of
the following health conditions:
- a fungal nail infection
- psoriasis of the nail
- warts that cluster around the
fingernail
- an overactive thyroid
- sarcoidosis – a condition where
small clumps of cells form in the organs and tissues of the body
- amyloidosis – where protein
builds up in the organs
- a problem
with the connective tissue fibres in the body that support the
organs and body tissues
- poor
circulation – for example, caused by smoking or Raynaud's phenomenon (a condition
where the blood supply to the fingers and toes is affected, causing them
to turn white)
- an
allergic reaction to medicine (usually to a type of antibiotic) or nail
cosmetics.
A loose nail should be cut back to where it's
detached to allow the nail to become reattached as it grows. You shouldn't
clean your nails with anything other than a soft nailbrush.
Indented spoon-shaped nails (koilonychia)
If your fingernails curve inwards like spoons
(koilonychia), you may have one of the following disorders:
- iron-deficiency anaemia
- haemochromatosis – where the body
retains too much iron
- Raynaud's phenomenon
- lupus erythematosus – a rare
condition where the immune system attacks the body's cells, tissues and
organs.
Pitting or dents on the nails
Pitting or small dents on the surface of your nails
can be a sign of any of the following conditions:
- psoriasis
- eczema – a long-term skin
condition that causes the skin to become itchy, red, dry and cracked
- reactive arthritis
- alopecia areata – a
condition that causes temporary bald patches on the scalp that are about
the size of a large coin.
Grooves across the fingernails (Beau's lines)
Deep lines or grooves that go from left to right
across the nail are known as Beau's lines. They may occur as a result
of:
- a
previous illness – the line forms at the time of the illness
- having chemotherapy
- a
previous injury
- previous
exposure to very cold temperatures, if you have Raynaud's phenomenon.
Illness, injury or cold temperatures can interrupt
nail growth and cause nail grooves to form at the base of the nails. The grooves tend to only be noticed a few months
later, when the nails have grown and the grooves have moved up the nails to
become visible. It takes about four to six months for a fingernail to fully
grow out, and six to 12 months for a toenail.
Unusually curved fingertips and nails
Clubbing of the fingertips means the tissue beneath
the nails thickens and the fingertips become rounded and bulbous. The
fingernails curve over the rounded fingertips. Clubbing is thought to be caused by increased
blood flow to the fingertips. It can run in families and be completely
harmless. However, if it suddenly develops, it may be a sign of one of many
possible medical conditions, including:
- long-term
lung disease or heart disease, such as lung cancer, bronchiectasis, or endocarditis
- inflammatory bowel disease – a
long-term condition that causes inflammation of the lining of the gut
- stomach cancer or bowel cancer
- cirrhosis (scarring of the liver)
- polycythaemia – a condition where the blood is too thick.
White lines running across nails
White spots or streaks are normal and nothing
to worry about, but parallel white lines that extend all the way across the
nails, known as Muehrcke's lines, are a sign of low levels of protein in
the blood. In contrast to Beau's lines, they're not grooved. They can
occur as a result of liver disease or malnutrition.
Dark stripes running down the nail
Dark stripes running down the nails (linear
melanonychia) are fairly common in black people over 20 years of age, and in
most cases it's perfectly normal. However, dark stripes shouldn't be ignored
because it can sometimes be a form of skin cancer that affects the nail bed,
called subungual melanoma. It's important that your doctor checks it to rule
out melanoma.
Subungual melanoma usually only affects one nail.
It will also cause the stripe to change in appearance – for example, it
may become wider or darker over time and the pigmentation may also affect the
surrounding skin (the nail fold).
Red or brown little streaks under the nails
If you have little red or brown streaks underneath
your nails, it's likely they're splinter haemorrhages – lines of blood caused
by tiny damaged blood vessels. A few splinters under one nail are nothing to worry
about, and are most likely caused by an injury of the nail. However, if
many nails are affected, the splinters may be a sign of lupus erythematosus, psoriasis, an infection of the heart valves (endocarditis) or
another underlying condition.
A destroyed nail
Nails can be destroyed by:
- injury,
including nail biting
- skin
conditions, such as psoriasis or lichen planus
- overgrowth
of the surrounding tissues, which is
usually harmless – for example, caused by a wart or verruca
- overgrowth
of the surrounding tissues caused by skin cancer (this is rare)
- nail patella syndrome – a rare
genetic condition which may cause missing nails, usually at birth.
You should see your doctor/ GP if one of your nails is destroyed and
you don't remember injuring it.
Painful, red and swollen nail fold (paronychia)
Paronychia is inflammation of the nail fold (the
skin and soft tissue that frames and supports the nail). It's most commonly caused by infection, injury or
irritation, and is about three times more common in women than in men.
Sometimes, it's associated with an underlying skin condition, such
as eczema or psoriasis, or another medical condition,
such as diabetes or HIV.
Paronychia can develop over a few hours (acute
paronychia). If it lasts for more than six weeks, it's known as
chronic paronychia.
Acute
paronychia
Acute infective paronychia usually starts after a
minor injury to the nail fold, such as from nail biting, picking or manicures.
The affected area is red, warm, tender and swollen. After a while, pus
can form around the nail and may lift the nail. Acute paronychia is often the result of a Staphylococcus infection, but it can
sometimes be caused by the virus responsible for cold sores (herpes simplex virus). In this
case it's known as herpetic whitlow.
Treatment for acute paronychia includes antibiotic creams or tablets. If there's a
large amount of pus, surgically draining it can help. With treatment, an
infected nail fold can clear up in a few days. If it isn't treated or doesn't
respond to treatment, the problem can become long-term (chronic).
Chronic
paronychia
Chronic paronychia often affects people who have
their hands in water for long periods, or come into contact with chemicals,
such as cleaners, bartenders, canteen staff or fishmongers. It may start in one nail fold but can affect
several fingers. The affected nail folds are swollen and may be red and sore
from time to time, often after exposure to water. The nail plate gradually
becomes thickened and ridged as it grows, and may become yellow or green and
brittle.
You must see your GP if the condition is severe. They may
prescribe antibiotic creams or tablets. In some cases, they may refer
you to a dermatologist (skin specialist). It can take months for chronic paronychia to clear,
and up to a year after that for your nails to return to normal. Keeping
your hands dry and warm, frequently using emollient hand cream and not biting or
picking your nails can help.
Source: NHS Choices