The sunken nails can be considered to be caused by the following reasons. If you are injured recently, it will cause congestion under the nail, which will lead to depression. You can use some drugs to remove blood stasis and build muscle after consulting the doctor, and pay more attention to the maintenance of the nail at ordinary times. If it is accompanied by such adverse symptoms as nail thickening, yellowing and turbidity, it may be caused by infected fungi. You can apply acetic acid solution or amorofen liniment to the affected area as instructed by your doctor, and take oral itraconazole capsules and other antifungal drugs. If you do not have regular work and rest and diet, it may be caused by malnutrition of A. The disease itself will generally improve itself, without too much worry, and may also recur. You can add more mineral tablets and eat more fruits and vegetables rich in vitamins.
