They may be among the smallest parts of your body, but your nails can be important indicators of your health.
In both Western and Chinese medicine, the shape and colour of nails reflect potential health problems, such as stress, nutrient deficiency, or even serious health issues like cirrhosis and cancer.
In Western medicine, tiny dark red spots on the nails, known as splinter haemorrhage, may suggest a potential heart problem, while a patch of tar yellow in the nail bed is typical of psoriasis, a skin disease.
Dr Grace Lam Si-wen , medical director of Skin Focus, adds that advanced liver problem may give rise to yellowish nails, while bluish or purplish nail colour reflects a potentially severe respiratory, heart or circulation problem, like decreased oxygen content in blood.
The shape of the nail can also signify health problems. 'Koilonychia is an abnormal shape of the fingernail: there are raised ridges, and the nail is thin and curved inward. This is associated with iron deficiency anaemia,' she said.
Lam adds that colour or shape changes can occur in finger and toe nails, and are just one sign of a potential disorder.
In terms of nail health, Chinese medicine echoes Western analyses, but looks more closely at the internal health system. Dr Lin Zhi-xiu, assistant professor of the Chinese University's school of Chinese medicine, says there are 12 meridians, or energy channels, in the body and these are connected to the nails. The meridians are believed to relate to different organs. Because they run through the blood system, health problems can show up in the nails.
Lin says bluish nails are caused by decreased oxygen content in the blood or poor blood circulation, while yellowish nails are caused by secretions of the gall bladder.
Healthy nails should be pink with a smooth surface. When they become paler, it can mean a deficiency of qi and blood; in Western terms, this is generally a sign of anaemia.
Lin adds that dark nails reflect blood stasis or congealed blood in the body, while a lot of black on the nails signifies serious liver problem like cirrhosis or liver cancer. Yellowish nails are sign to jaundice or 'damp heat' or infection in the liver and the gall bladder. Bumps on the nails are caused by severe stress and anger.
Both Chinese and Western medicines recommend a well-balanced diet. Lam advises a diet rich in vitamins A, E, B complex - especially biotin - zinc and iron for nail growth.
'Egg yolk, liver, and dark, leafy vegetables contain biotin; mussels and nuts contains zinc; and iron can be found in lean beef and spinach,' Lam says. Vitamins A, B and E are found in most fruits and vegetables.
Lin adds it is important to reduce stress to improve your circulation, and eat plenty of red meat; vegetarians can eat more celery, green onions and garlic, instead.