Hello Masterbation neither cause back pain not dandruff and hair fall so you need not to worry In my opinion you should get an X ray done for lumbo sacral spine and you can take painkiller like diclofenac or ibuprofen. If it still doesn t subside than you may require AN MRI scan for confirmation of diagnosis Meanwhile you should avoid lifting heavy weight, sudden bending forward, sleep on a hard bed and correct your posture and gait. Dandruff and hair fall might be related to infection, allergic reaction or nutritional deficiency Hair fall could be related to genetically determined baldness if your father has less hairs Hope this answers your question Please feel free to discuss further I will be happy to help you Best wishes