CCDs are illnesses that are long in duration and often do not improve on their own.  In many cases, the causes of these diseases are unknown.

• Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS)
• Fibromyalgia Syndrome (FM)
• Chronic Lyme-Like Syndrome
• Multiple Chemical Sensitivities 

CCDs are called complex conditions because:

• The factors involved in causing these conditions are not well understood.
• The symptoms and effects of any CCD can vary greatly among people with the same condition.
• The longer duration of a CCD can lead to other health complications. These can include physical problems such as weakness, fatigue, and difficulty with daily activities (functionality). 
• Any long-term illness can impair relationships, education and career goals, and affect a person’s mental health.

With all of these conditions, there are no blood or other laboratory tests to confirm a diagnosis. These conditions are diagnosed according to the particular group of symptoms described by the patient.

Each person with a CCD will experience their disease in a unique way, with symptoms that may or may not exactly match the most common descriptions. The most helpful approach to treatment will identify patients’ needs according to their symptoms and day to day functionality.

Even if you have had a CCD for a long time, there are steps you can take to feel better and gradually improve your condition. Having your CCD diagnosed as early as possible will help with a better and more rapid recovery.