A letter from your doctor can help you with your Social Security Disability case. The most important thing to remember is that it is not necessarily your condition that matters, but the way your condition limits your activities. The reason for this is the Administrative Law Judge is asking himself whether you can do your old job or any other job. A letter from a doctor that explains you are limited in lifting, walking and sitting is helpful if it explains why you have this limitation. Such as, the bulging disc is pressing on the nerve root causing pain down the right leg. Other examples of limiting factors are pain, fatigue, and side effects from medications.A statement that you are disabled or unable to work without supporting explanation will not help you win your case. When your doctor understands what Social Security is looking for, then the doctor can often help your case a great deal.