Osteoarthritis
Rheumatoid arthritis
Lupus erythematosus

Sub conditions:

Spondyloarthropathy
Temporomandibular disorders (TMJ)
Costochondritis
Carpal tunnel syndrome
Joint hypermobility

However, enough about me ... since this issues are so common to us with FM, I feel it meet to discuss some of the issues and treatments that are common to all of the above, and how they can interact with FM.

"Osteoarthritis (OA, also known as degenerative arthritis, degenerative joint disease), is a clinical syndrome in which low-grade inflammation results in pain in the joints, caused by abnormal wearing of the cartilage that covers and acts as a cushion inside joints and destruction or decrease of synovial fluid that lubricates those joints. As the bone surfaces become less well protected by cartilage, the patient experiences pain upon weight bearing, including walking and standing. Due to decreased movement because of the pain, regional muscles may atrophy, and ligaments may become more lax. OA is the most common form of arthritis.

The main symptom is chronic pain, causing loss of mobility and often stiffness. "Pain" is generally described as a sharp ache, or a burning sensation in the associated muscles and tendons. OA can cause a crackling noise (called "crepitus") when the affected joint is moved or touched, and patients may experience muscle spasm and contractions in the tendons. Occasionally, the joints may also be filled with fluid. Humid weather increases the pain in many patients.

OA commonly affects the hands, feet, spine, and the large weight-bearing joints, such as the hips and knees, although in theory, any joint in the body can be affected. As OA progresses, the affected joints appear larger, are stiff and painful, and usually feel worse, the more they are used throughout the day, thus distinguishing it from rheumatoid arthritis.

In smaller joints, such as at the fingers, hard bony enlargements, called Heberden's nodes (on the distal interphalangeal joints) and/or Bouchard's nodes (on the proximal interphalangeal joints), may form, and though they are not necessarily painful, they do limit the movement of the fingers significantly. OA at the toes leads to the formation of bunions, rendering them red or swollen. OA is the most common cause of water on the knee, an accumulation of excess fluid in or around the knee joint. "Wikipedia

Despite what the name implies, it is not a matter of only time that creates this problem. Given as I was not even out of my teens when it first showed up, would seem to suggest that time is not really a factor here. Further, there are those who are literally born with the disorder.

Now, what this disorder means for your average person, is a life long series of ups and downs, as pain waxes and wanes, according to inflammation and the amount of damage done. Please note, that with this form, excess use, brings on more pain, rather than the reverse.

Approximately, 60% or more, of FMers, have symptomatic Osteoarthritis. I say symptomatic, for the simple reason, that a good 80% of the population, will, at some point, ( Normally by age 65 ) show the classic signs of this disease on x-ray, however, only some 60% of those, will know about it due to pain and disability.

Treatment of Osteoarthritis:

What is interesting to note, is the recommended treatments for Osteoarthritis, are almost identical, with the typical recommendations for FM. Mayo Clinic
other than, a few important differences, re injections into the joints and various surgeries for joint replacement. They are offered a few other NSAID types and various anti-inflammatory medications, and more immediate access to stronger pain medications, but otherwise, the recommendations are nearly identical with FM and Pain Management on site link. Which means, short of using some of the more typical medications for this condition, most anything you do for your FM, will be of benefit ( or lack thereof ) for your arthritis.

"Rheumatoid arthritis (RA) is a chronic, systemic auto immune disorder that causes the immune system to attack the joints, leading to arthritis (inflammation of the joints), as well as other organs of the body such as the lungs and skin. It can be a disabling and painful condition, which can lead to substantial loss of functioning mobility due to pain and joint destruction."

This is a much more serious form of arthritis, mainly due to the fact it can totally destroy the joints in question, causing much deformity and pain. Further, the joints are not the only things subject to damage. The kidneys, eyes, skin, liver and much more, can be damaged by this disease. This disorder is often found in standard blood work, having what is called an RA factor. This test often misses it however, and more specific tests called anti-citrullinated protein antibodies (ACPA) have been developed, which are much more accurate.

Treatment for this disease is much more dependent on medications, a rather long list of them, see. Mayo Clinic

The most common treatments are:

Medication to relieve pain and inflammation
Rest to let injured tissues heal themselves
Exercise to rebuild mobility and strength

Please note that modification of pain, is first in the list. Then you get into the more mundane treatments such as, regimens of heat, rest, and exercise; physical therapy; and controlled application of deep heat to soothe affected joints. As well as, yet again, almost identical suggestions are are given those with FM. And like its lesser cousin, Osteoarthritis, there is a higher access to stronger pain medications. As with other forms, most things you do to aid your FM, will aid RA. Only a small percentage of FMers (25%) fit the classic definition of having RA.

This is one to make special note of, for the simple reason, it and FM, are often mistaken for each other.

"Systemic lupus erythematosus (SLE or lupus) is a chronic auto immune disease that can be fatal, though with recent medical advances, fatalities are becoming increasingly rare. As with other auto immune diseases, the immune system attacks the body's cells and tissue, resulting in inflammation and tissue damage. SLE can affect any part of the body, but most often harms the heart, joints, skin, lungs, blood vessels, liver, kidneys and nervous system. The course of the disease is unpredictable, with periods of illness (called flares) alternating with remission." Wikipedia

Fatigue
General discomfort, ill feeling (malaise)
Sensitivity to sunlight
Joint pain and swelling
Arthritis
Swollen glands
Muscle aches
Nausea and vomiting
Pleurisy (causes chest pain)
Fingers that change color upon pressure or in the cold
Numbness and tingling
Abdominal pain
Thought and concentration disturbances
Sleep disorders

Other signs:

Fever
Skin rash -- a "butterfly" rash over the cheeks and bridge of the nose
Mouth sores
Hair loss
Blood in the urine
Coughing up blood
Nosebleed
Swallowing difficulty
Skin color is patchy
Red spots on skin

Given the overlap of the first set of signs, and the signs of FM, it is easy to see why it is often confused with FM, unless other factors are taken into account. And yet again, the advent of treatment, other than some disorder specific drugs, the need for sun screen and the like, the suggestions for treatment, are nearly identical to the suggestions given for FM. 90% of those with Lupus, are women. Those with Lupus primary who have FM, is a small percentage, at 22%.

Spondyloarthropathy:

"Reactive arthritis is considered a systemic rheumatic disease. This means it can affect other organs than the joints, causing inflammation in tissues such as the eyes, mouth, skin, kidneys, heart, and lungs. Reactive arthritis shares many features with several other arthritic conditions, such as psoriatic arthritis, ankylosing spondylitis, and arthritis associated with Crohn's disease and ulcerative colitis. Each of these arthritic conditions can cause similar disease and inflammation in the spine and other joints, eyes, skin, mouth, and various organs. In view of their similarities and tendency to inflame the spine, these conditions are collectively referred to as "spondyloarthropathies." Med net

This is brought about by an infection, and is easily identifiable. Treatments are drug specific, with protection for the effected areas. There are no current figures, for those with FM and this condition.

"Temporomandibular joint disorder (TMJD, TMJ or TMD), or TMJ syndrome, is an umbrella term covering acute or chronic inflammation of the temporomandibular joint, which connects the lower jaw to the skull. The disorder and resultant dysfunction can result in significant pain and impairment. Because the disorder transcends the boundaries between several health-care disciplines — in particular, dentistry, neurology, physical therapy, and psychology — there are a variety of quite different treatment approaches. The temporomandibular joint is susceptible to many of the conditions that affect other joints in the body, including ankylosis, arthritis, trauma, dislocations, developmental anomalies, and neoplasia." Wikipedia

Some 75% of FMers, present with the signs of TMJ. They are:

Pain or tenderness of the jaw
Aching pain in and around the ears
Difficulty chewing or discomfort while chewing
Aching facial pain
A clicking sound or grating sensation when opening your mouth or chewing
Locking of the joint, making it difficult to open or close your mouth
Headache
Uncomfortable or uneven bite

Bruxism, or night time clenching of the jaw, is a major culprit ( see sleep disorders on site link ), and of course most forms of arthritis.
Other than Occlusal Splints ( a devise to help keep you from grinding your teeth ) the treatments of NSAIDS, rest, exercise of the jaw, moist heat, etc., are much the same as for any other arthritis type of problem.

"Costochondritis is an inflammation of the cartilage that connects a rib to the breastbone (sternum). It causes sharp pain in the costosternal joint — where your ribs and breastbone are joined by cartilage. Pain caused by costochondritis may mimic that of a heart attack or other heart conditions." Mayo Clinic

Common signs are:

Pain when taking deep breaths
Pain when coughing
Difficulty breathing

Of note:

Exacerbated by trunk movement, deep inspiration, and/or exertion
Lessens with decreased movement, quiet breathing, or change of position
Sharp, nagging, aching, or pressure
Usually localized but may extend or radiate extensively
May be severe
May wax and wane

This is one of the few that is considered an FM sign in and of itself. Given as one of the tender points is in this area.

Treatments

NSAIDS for pain control
Local heat
Local infiltration of local anesthetic, steroid, or intercostal nerve block
Biofeedback
Gentle stretching of the pectoralis muscles

As before, most treatments, are consistent with the treatments suggested for FM.

"Many people with carpal tunnel syndrome have gradually increasing symptoms over time. The first symptoms of CTS may appear when sleeping and typically include numbness and paresthesia (a burning and tingling sensation) in the fingers, especially the thumb, index, and middle fingers. These symptoms appear at night because many people sleep with bent wrists which further compresses the carpal tunnel. If the median nerve is already under stress, the increased compression of the bent wrist results in numbness and tingling. Difficulty gripping and making a fist, dropping objects, and weakness are symptoms of progression. In chronic cases, there may be wasting of the thenar muscles (the body of muscles which are connected to the thumb)." Wikipedia

Hypothyroidism, on site link, Osteoarthritis ( see above ) and diabetes were most often associated with carpal tunnel syndrome. Also common are repetitive stress injuries, brought on by; Power tools Typing, Construction work; Percussion instruments, in short, anything that causes repeated trauma to the wrist.

Treatments:

Hand splints, to rest the joint
Physiotherapy
Steroid injections
Cortisone injections
NSAIDS
Surgery

Depending on the severity, rest and therapy, as well changes in whatever movements or actions that are contributing to it, might help. Surgery is a last resort, as while it does have a decent success rate, its failure rate is also high. Some 55% of FMers, present with the signs of Carpal tunnel disorder.

Is an interesting problem, in that I personally feel is somewhat under researched. It is, in effect, where the joints can move too far, in any direction, but has much further effects than that. For example, during stretching exercise, it is common for those of us with FM, to over extend, and therefore injure the joint, this is possibly due to this hyper flexibility. This factor is yet another disorder that is commonly classed as a sign of FM, and in fact is considered to be a problem of misdiagnoses in some cases. Study on Joint hypermobility and FM

"Hypermobility can cause joint pain and results in a higher incidence of dislocations, sprains and secondary Osteoarthritis" Mayo Clinic

Gastroesophageal Reflux Disease (GERD) *
Irritable Bowel Syndrome (IBS) *
Varicose Veins
Idiopathic scoliosis ( spinal deformity )
Joint instability causing frequent sprains, tendinitis, or bursitis *
Early-onset Osteoarthritis *
Subluxations or dislocations, especially in the shoulder. *
Knee pain *
Back pain, prolapsed discs or spondylolisthesis *
Hernias
Bruising *
Headaches *
Susceptibility to whiplash
Temperomandibular Joint Syndrome also known as TMJ *
Increased nerve compression disorders (i.e. carpal tunnel syndrome) *
Mitral valve prolapse *
Uterine prolapse * ( common problem for women with FM)
Worsening of symptoms in cold weather *
Joints that make clicking noises

As you can see, again, we have a large overlap here, of signs and symptoms, common to FM ( see *) Medical treatment is nearly identical to FM to the point of also including antidepressants, and the anticonvulsants, like gabapentin. These are used, along with NSAIDS and steroid injections. Of note, is the difficulty in doing stretching exercise, a fact we with FM are told to do, repeatedly. If however, Hypermobility is more of an issue, that is currently believed, this could be a problem, unless, the exercises are done very carefully, to avoid doing damage. Some 81% of persons with FM, fit the definition of Hypermobility.