• 23101 Sherman Place Suite 507 West Hills, CA 91307

  • 818-598-0000

yelp logo Instagram logo Linkedin logo Google plus logo Youtube logo

How do I know if I have Osteoarthritis or Rheumatoid Arthritis?

Osteoarthritis and rheumatoid arthritis are both forms of arthritis, and can cause joint tenderness and deformity. This is where their similarity stops, as they are actually very different diseases.


Tire photoOsteoarthritis is a form of mechanical arthritis. It is caused by wear and tear of the cartilage and joint, much like the tires of a car. The more we use our joints, in activities like sports or repetitive movements, the more likely we are to get osteoarthritis.
Osteoarthritis is very common, and its prevalence increases as we get older. In fact, 35% of people over 65 and 80% of people over 75 have at least one arthritic joint.

Osteoarthritis can affect any joint, but it’s mostly seen in large joints like hips and knees. The arthritis pain is usually worse at the end of the day or after a lot of activity. Stiffness in the morning lasts a few minutes.

Rheumatoid arthritis

joints of hands photoRheumatoid arthritis is caused by an overactive immune system. The immune system actually attacks the joint, causing a lot of inflammation which can actually dissolve pieces of the bone. I sometimes think of this as pacman eating away at a joint. It can start at any age. Its prevalence is about 1% in the United States.
Rheumatoid arthritis most commonly affects small joints of hands and feet, but like osteoarthritis, can go to any joint. The pain is usually worse in the morning and after periods of inactivity. Morning stiffness commonly lasts several hours. Pain and stiffness get better as the day progresses.


Here are the differences between the two diseases at a glance:

OsteoarthritisRheumatoid Arthritis
CauseWear and tearAutoimmune
PrevalenceIncreases with ageAbout 1% of population
GenderWomen > MenWomen > Men
Joint sizeUsually large jointsUsually small joints
InflammationUsually littleUsually a lot
TimingPain worse at nightPain worse in morning
Morning stiffnessLess than an hourMore than an hour


Unfortunately, most arthritis is not this simple. For example, you can have osteoarthritis affecting small joints of the hands, or rheumatoid arthritis with not a lot of inflammation.  Or you may have one of more than 100 other types of arthritis. The diagnosis will require a trained physician. If you have arthritis pain, it is a good idea to talk to your physician or see a rheumatologist.



Only one type of arthritis? NOT!

Arthritis literally means inflammation in the joint. It can cause pain, swelling, and limitation in range of motion of a joint. When I talk about different types of arthritis, some of my patients are surprised- “What, you mean there is more than one kind of arthritis?”

The answer is yes. In fact, there are more than 100! The most common type of arthritis is osteoarthritis, affecting 3 out of 5 of us by the time we are 65. Most people have also heard of rheumatoid arthritis, which is an autoimmune disease, and gout, which is caused by deposits of uric acid crystals in a joint. There is also arthritis caused by infection, deposition of other crystals, and many connective tissue diseases such as lupus or scleroderma.

So how do we differentiate between the different types of arthritis? I usually like to divide them into two categories:

1) Mechanical arthritis
2) Inflammatory arthritis

Mechanical arthritis would include osteoarthritis which is caused by wear and tear of a joint. Also in this category would be joint pain caused by trauma, tendonitis or tendon rupture. Even though there may be a lot of fluid in the joint, there are usually not too many white blood cells in the fluid- ie the fluid is not inflammatory.

I include just about everything else under “Inflammatory arthritis”. The immune system is usually involved in these forms of arthritis, causing there to be a lot of white blood cells in the joint fluid. Examples are rheumatoid arthritis, gout, psoriatic arthritis, and others.

Why is this important? Because different types of arthritis are treated very differently. Glucosamine, which may be helpful in osteoarthritis, will not help gout. Miracle drugs for rheumatoid arthritis, like Enbrel and Humira, are actually dangerous if the arthritis is caused by an infection.
So I would say that if you are experiencing joint pain, the most important first step is to find out what type of arthritis you actually have. You can then work with your rheumatologist to come up with the best treatment option for you.