Hard lumps on the left side of the navel may be related to skin diseases, intestinal diseases, persistent bowel movements and other reasons. 1. Skin diseases: such as subcutaneous fibroma, sebaceous cysts, boils and other skin diseases, can protrude from the surface of the skin, which can be manifested as hard lumps on the left side of the navel. In addition, the rectus abdominis myoma and other lesions can also be manifested as hard lumps. 2. Intestinal diseases: such as colon tumor, intestinal obstruction and other intestinal diseases, if the tumor volume is large, or intestinal obstruction distension is serious, can be felt in the left side of the navel hard lump. 3. Hangover: when there is hangover, you can also feel the hard lump on the left side of the navel, which is hangover. The left side of the navel with hard lumps if the discomfort symptoms, need to go to the hospital in a timely manner, after a clear diagnosis, under the guidance of the doctor for standardized treatment, so as not to delay the condition.