The causes of breasts lying on the side with pressure pain and heat sensation are acute mastitis, breast hyperplasia, breast hypertrophy and so on. 1. Acute mastitis: When the body’s immunity decreases, or the milk is stagnant, it is easy to lead to bacterial invasion, triggering acute mastitis. Secondly, endocrine dysfunction may also cause this disease, manifesting the phenomenon of side lying pressure pain and a feeling of heat. For this situation, you can take benzoxiline sodium, cefradine, bromocriptine and so on to treat. Secondly, you should do a good job of cleaning the nipples and try to ensure that the stagnant milk is discharged. 2. Breast Hyperplasia: If the ratio of estrogen to progesterone is out of proportion, it may cause the problem of hyperplasia in various parts of the breast. In addition to pressure pain and heat sensation, there may also be symptoms of nipple overflow. Most patients can heal through daily care and try to avoid stimulating foods. Next, strengthen psychological guidance and maintain a positive attitude towards life. In addition, if the symptoms are more serious, you can also use triamcinolone acetonide to relieve pain. 3. Breast Hypertrophy: The cause of breast hypertrophy is complex, mostly due to hormonal disorders. In the face of this disease, it is recommended to use drugs to balance the body’s hormone levels, commonly used in the methylhydroxyprogesterone, tamoxifen and so on. Additionally adult women or those with severe conditions can also undergo surgery for liposculpture. In life, many diseases may cause the phenomenon of breast lying on the side with pressure pain and a feeling of heat. If the pain lasts for a long time and shows signs of aggravation, you should seek medical attention as soon as possible and follow medical advice.