SINGAPORE - Take a look at your fingernails and check if they are smooth and free of discolouration - these are key signs that they are healthy.
But if your nails have changed in colour, texture or thickness, these symptoms may point to an underlying health condition.
Dr Joyce Lim of Joyce Lim Skin and Laser Clinic said there are times when one's nails hint at a medical condition that one is not aware of.
"For example, the person may have spoon-shaped looking nails (called koilonychia), which indicates that he has anaemia," said Dr Lim.
Most of the time, however, the condition of one's nails is a manifestation of other medical conditions which the patient may already be aware of, she said.
For instance, yellow nails are seen in people with renal disease, while white nails are seen in those with a protein deficiency or liver disease.
"Sometimes, by looking at the nails, we can predict an event that happened a few months ago. For example, there may be horizontal ridges on the nails - known as Beau's lines - which correspond to an illness or surgery," said Dr Lim.
"As it takes six months for a nail to grow out, if the beau's line is in the middle of the nail, it would signify that there was a medical event three months ago."
Although nail changes accompany many conditions, many of these abnormalities are harmless - for instance, not everyone with white nails has liver disease, pointed out Dr Paul Chia, a specialist in dermatology and a consultant at Raffles Skin & Aesthetics Centre.
And while nail changes are linked to our internal health, they are usually not considered a disease in itself, he added.
The clubbed nail - which occurs when the tips of the fingers enlarge and the nails curve around the fingertips - is not a disease, but it may indicate problems with the bowels, lungs or heart.
"Conversely, certain nail disorders may be part of a skin condition, such as psoriasis," said Dr Chia. This often causes the nails to be crumbly and have an unsightly yellow tinge.
Such a problem can be treated with creams, injections or medicine, he said.
Fungal infection of the nails, too, can be treated with a variety of methods, including topical anti-fungal cream, oral anti-fungal medication and, less commonly, surgical nail removal, he said.
This article was first published on Aug 14, 2014. Get a copy of Mind Your Body, The Straits Times or go to straitstimes.com for more stories.