You apply while you are still working.
You are still working. Even if you are only working part-time, the fact that you are working is a strong indicator you are not disabled. It is evidence that despite your disability you can still earn a living. Unfortunately, you may have to work out of necessity but this will probably lose you your claim right away. Social Security may not even allow you to apply.
No Severe Impairment
You do not have a severe impairment. You feel you cannot work any longer. That is not going to be sufficient. Generally, you are going to have to have an impairment that adversely impacts your daily activities. Just having hypertension and some aches and pains is not going to be enough.
You have not worked enough
You have not worked enough. If your work has been sporadic or if you have been paid under the table, then you may not have sufficient quarters to qualify for Social Security Disability. This often trips up a housewife who applies who has stayed home and out of the work force to raise children. I am afraid you get out what you pay in.
You are too young under Social Security rules
You are too young. Social Security regards everyone under age 50 to be in the "young category." When you are in the "young category" it is not enough to show you have a severe impairment and that you cannot do your usual work. In this category you usually have to show you cannot do any kind of light duty jobs. If you are in this category you may want to see if your State Department of Rehabilitation cannot re-train you.
You are on Unemployment Compensation
You are receiving unemployment compensation. In order to receive unemployment compensation you have to certify you are "able to work" and you have to show you are looking for work. Most Social Security Judge feel being on unemployment compensation is not consistent with a disability claim.
You are disabled but your disability will not last 12 months
Your disability has not lasted 12 months and is not expected to last 12 months. You have had an operation and you are unable to work. However, if you are going to recover within 12 months, you do not have a valid Social Security Disability claim. Social Security is just not a short term disability program.
You lack medical treatment for your impairment
You have an impairment but you have not had consistent medical care for the impairment. Social Security will not accept your statements about your medical condition without medical proof of that impairment. You may be sent to their doctor but this will be a perfunctory physical examination which rarely proves disability. Even if you lack health insurance, you have to go to free clinics and obtain medical care to prove your disability.