Hi and welcome to HCM I would like to know since how long you are facing this problem. And if you have any history of any allergies whatsoever since childhood or history of asthma.etc. Judging by your history it could be an insect bite probably bed bugs or the flies around light fittings at nighttime, or mosquitoes, ants etc You will need to keep a track of how often it happens and at what intervals. Keep a note of travel ,outdoor or indoor activities, or particular foods you eat on these days. Any tablets/medicines you take which may cause this. There are a large number of substances that can cause such hives and your symptoms seem allergic.You will need to keep a close watch on what could be the cause and avoid it. Also if you are stayin in a hostel/sharing accommodation or have kids around you are more prone to infestations. They usually cause itching and bumps at night when they feed. Tests that you can do if it s persistent include allergy panels for various common causes which can detect the cause. For now apply a calamine based lotion regularly to soothe the skin and take a week s course of antihistamines - avil, levocet etc. at night. If it persists or is recurrent and no cause can be found visit a doctor for advanced tests.