Finger belly with horizontal lines is considered a normal phenomenon, contact with irritating substances and irritating dermatitis and other reasons. 1. Normal phenomenon: due to each person’s physical condition is not the same, some people will appear in the belly of the finger with horizontal lines, not accompanied by any symptoms, such as pain, itching, etc., is a normal physiological phenomenon. In addition, hands soaked in water for a long time, finger skin thickening after absorbing water, may also appear horizontal lines. After leaving the water, it will gradually subside by itself. 2. Contact with irritating substances: If the fingers are in contact with acidic or alkaline irritating substances, due to corrosion of the stratum corneum, there may be horizontal lines on the finger belly. 3. Irritant dermatitis: due to inflammation stimulation, can lead to finger belly redness, swelling, itching, keratinization and other conditions, may also cause finger belly with horizontal lines. If the finger belly has horizontal lines and accompanied by abnormal symptoms, patients need to go to the hospital in time, do not delay the disease.