What is gynecomastia? The answer is very straightforward: It is the abnormal enlargement of the male breast. However, there is a range of male breast swelling or gynecomastia causes and understanding these can help work out how to get rid of the problem. In most cases there are few symptoms associated with the breast swelling, and it is not usually painful. The most common time for male breast tissue to grow is during puberty when up to 70% of boys are affected. Things as varied as foods, prescribed drugs, recreational drugs (most commonly marijuana or steroids), or illness in other areas of the body can all lead to man boobs. Occasionally there is a serious cause for the breast swelling and it can be helpful to use a symptom checker to see if an urgent trip to the doctor is needed. Worrying symptoms can include unilateral swelling, severe pain or separate lumps – either in the breast or in another part of the body. For most people, male breast swelling will either settle down on its own or get better with the help of diet and exercise. Stopping recreational drugs is always advised, and a doctor should be consulted about whether prescribed medication needs to be changed. If the problem persists, the most effective treatment is often surgery, although this needs to be thought about carefully.