The pain and swelling of the tip of the index finger may be caused by trauma, onychomycosis, joint inflammation and so on. 1. Trauma: when the patient’s fingers are overworked, traumatized, bruised and swollen, or the local skin of the index finger breaks down, causing bacteria to enter the tissue space along the breach, it can cause acute suppurative infections, which may result in localized obvious swelling and pain. 2. Inguinitis: Inguinitis is an inflammation of the tissues around the nails of the hands and feet, which may be caused by a variety of pathogens, and the patient may have symptoms such as redness, swelling, heat and pain of the local tissues, and in severe cases, it may turn into pus, and when the patient develops inguinitis in the index finger, it may cause pain and swelling of the fingertip. 3. Joint inflammation: when the patient suffers from gouty arthritis, rheumatism or rheumatoid arthritis and other joint inflammation, when the arthritis inflammation acute attack, there may be pain and swelling of the index finger tip. It is recommended that patients seek timely medical examination to clarify the cause of the disease for targeted treatment, pay attention to observe the affected area in life, if there is a worsening of the symptoms or other discomforts in time to seek medical treatment.