The Social Security Disability program exists to provide a substitute income for people who are no longer able to work. If you work long enough at a job, which is covered under the provisions of the Social Security Act, and become disabled, you are probably eligible for Social Security Disability benefits.
According to the Social Security Administration, a "disability" can be physical, or emotional, or some combination of both. In order to win benefits, you must have a disability severe enough to keep you from working in any regular paying job for at least 12 consecutive months. The test for eligibility for Social Security Disability benefits is not whether you can go back to a job you have lost. It is not whether you have been able to find a job recently. The test is whether you are physically and emotionally capable of doing a job that is generally available in the national economy.
To obtain Social Security Disability benefits, you must have a doctor state that you are disabled. Your doctor's opinion should be supported by clinical findings and/or laboratory findings. Unfortunately, many genuinely disabling conditions are difficult to diagnose by objective testing. In cases like that, you can use a lawyer's help to present your doctor's reports properly, and to convince the government that you deserve Social Security Disability benefits.