Juvenile Idiopathic Arthritis (JIA) – This is an umbrella term for conditions that occur in children who have chronic arthritis. It includes polyarthritis rheumatoid factor positive, systemic, polyarthritis rheumatoid factor negative, psoriatic arthritis, oligoarthritis, undifferentiated arthritis, and enteritis-related arthritis. Because there are so many potential categorizations, estimating the total number of cases is difficult, but it is believed to be between 70,000 and 100,000 in the United States.

Osteoarthritis – This is the most common form of arthritis, which typically happens to older people whose bodies have been stressed and strained over the years by work, but also can be caused by obesity or joint injuries. The hips, knees, spine and feet are the typical locations for this form of the disease, which arrives gradually and causes pain. It usually is not accompanied by fatigue or other issues.

Rheumatoid Arthritis – Sometimes called by its initials, RA, this happens when the immune system attacks certain areas, mostly the joints. The result is severe inflammation and joint damage, which can result in skin lumps called rheumatoid nodules. These are often found on the elbows, heels or over the knuckles. Researchers still do not know the cause, but feel that the immune system is compromised by a virus or infectious bacteria that starts in the joints and then spreads. Swelling in the afflicted areas and severe pain in those locations is the consequence, and it makes daily life hard, as walking, driving, working and even opening a jar become difficult.

Psoriatic Arthritis – As the name implies, the patchy, red and white, scaly skin condition known as psoriasis plays a prominent role in those who have this condition. The tips of elbows and knees can stiffen and develop the skin condition. However, there is no tie-in between regular psoriasis and psoriatic arthritis. Having the skin condition does not mean you will develop psoriatic arthritis. This form of the disease usually occurs after age 30 and is equally found in men and women. It is usually localized and having it one knee, elbow or finger is not uncommon.