Red bumps on the waist are considered to be related to allergy, urticaria, folliculitis, shingles and so on. 1. Allergy: daily contact with allergic substances such as pollen, animal fur, chemical fibers, etc., and consumption of allergic foods, resulting in an allergic reaction, may appear in the case of red bumps on the waist. 2. Urticaria: mainly caused by food allergies, infections, autoimmune abnormalities, etc., often showing itchy skin, wind, etc., which may lead to the appearance of red bumps on the waist. 3. Folliculitis: mainly caused by bacterial infection, skin trauma, excessive sweating, make-up, etc., often showing red papules centered on hair follicles, accompanied by itching and pain, which may lead to the appearance of red bumps on the waist. 4. Herpes zoster: mainly due to viral infections, low immune system, mechanical trauma, etc. can also trigger the disease, often showing blisters, pain, etc., may lead to the appearance of red bumps on the waist. Therefore, red bumps on the waist should be taken seriously, if the symptoms do not get better or aggravated, it is recommended that you should choose to seek medical attention and follow the doctor’s instructions for treatment.