Hard lumps under the chin are mainly seen clinically in the following cases: 1, subcutaneous bruising due to trauma, when the soft tissue of the skin is injured, the affected tissue will show redness, swelling, heat, pain or redness of the skin, and then turn into bruises and bruises, and the patient feels hard lumps when touched; 2, inflammation of lymph nodes, commonly found in the jaw, and there is a rich lymph node system in the head, face and neck, and lymph nodes are an immune organ whose main function is interception and removal of some bacteria and necrotic substances, so there will be temporary swelling of lymph nodes. If painful and swollen lymph nodes are touched, it mostly indicates inflammation in the body; if painless and swollen lymph nodes are touched, it may be a signal of cancer, and detailed examination should be done in hospital to exclude the possibility of cancer. 3. Eating spicy and stimulating food in daily life will easily cause the body to get on fire, and swollen lymph nodes will also appear.