Many Americans are affected by 9/11-related illnesses, but some are not getting the help they need.

Doctors say the blame for some neurological conditions stem from toxic chemicals that became airborne when the towers came crashing down.

Unfortunately, some first responders suffering from these ailments are not covered by the World Trade Center Health Program. "We're seeing case after case of rheumatologic disease, autoimmune disease, neurological conditions, conditions nobody can even explain and we believe these are due to the large number and variety of chemicals taken into the body," says Dr. Marc Wilkenfeld.

One health care advocate says it's difficult to prove auto-immune diseases and neurological disorders are related to the attacks. However, they could get added to the program in the future.