1. Men with a family history of breast cancer.
2. Low testosterone and hormonal imbalance in the body.
3. Men who have ever suffered from gynecomastia or obesity.
4. The testicle has been injured or removed, or the patient has suffered from cryptotestis.

Generally, men don't notice breast lumps and often realise until bleeding or pussing before seeking medical treatment. The methods used by women to examine breast abnormalities are also applicable to men.

1. Painless lumps appear: Most breast cancers in men are located in the lower breasts. If you find a lump under the areola, you should pay attention because this area happens to be where male breast tissue is mostly found.
2. Abnormal nipple shape: In clinical research, 20% of men with breast cancer will have symptoms of inverted, scabbed, or retracted nipples.
3. Changes in skin: Chest skin or chest muscles may have changes, such as red rash or adhesion, which may be signs of breast cancer.
4. Nipple discharge: Nipple discharge is one of the common symptoms of breast disease. According to statistics, patients with nipple discharge as the first symptom account for 3% to 14% of breast disease cases, and it is also one of the signs of breast cancer.
5. Lymph nodes appear in the armpit: You should also pay attention if there are lymph nodes in the armpit. This is a standard symptom of breast cancer. Usually more than one lymph node will grow.

Men should also pay attention to the changes in their breasts at all times. Once an abnormality is discovered, you should seek medical consultation immediately.