While sleeping i suffer from chest tightness mainly on the right chest and right elbow pain.i experience right knee pain too..what could be the cause?

Hard to say: Pains at night can be a normal result of activities during the day, and even arthritis which is commonly worse at night. Chest tightness is a concerning symptom, especially for a man in his mid 40s. It can suggest a serious problem like heart disease, or more commonly, reflux, or something like asthma. You have several things that may or may not relate. As you are suffering, best to get good exam.