I think a page dedicated to similar conditions to Fibromyalgia would be very helpful to a lot of people. Fibromyalgia is difficult to diagnose due to there being no specific test for it and this could lead to a lot of people being misdiagnosed. On this page I will focus on other conditions that can appear very similar to Fibromyalgia, in their symptoms. I will also list the symptoms that are unique to Fibromyalgia, so people can tell them apart. So if you’re not convinced about your diagnosis, this page would be worth a read. Remember it is not possible for you to diagnose a new condition for yourself, using the information on this site, so if you think that your diagnosis is wrong, it is important that you speak to your doctor about your concerns and take things from there.

CFS/ME (Chronic Fatigue Syndrome / Myalgic Encephalomyelitis)

I have started with CFS/ME as there is not much of a difference between CFS/ME and Fibromyalgia. As such I have asked medical professionals what the differences between the two are and not many can confidently answer the question. Some even believe they are the same thing. If you assume that they are different conditions, then it is widely accepted that a lot of people diagnosed with CFS/ME, actually have Fibromyalgia and a lot of people diagnosed with Fibromyalgia, actually have CFS/ME.

My understanding is that patients with CFS/ME have the primary problem of a malfunctioning battery. If you understand the physics of rechargeable batteries and how they deteriorate, you might understand what I mean. I mean that patients struggle to recharge themselves fully, run out of energy faster than normal and have trouble pacing themselves. The amount of energy they have from one day to the next is vastly different. As with Fibromyalgia when the patient becomes tired, the body becomes more sensitive to pain and the fatigue/pain cycle starts.

This is different from Fibromyalgia, in that although patients have the same problems with pacing and with the fatigue/pain cycle, their main problem is with sleep. Patients with Fibromyalgia have various sleep problems and often fail to get a proper night’s sleep. It can be difficult for them to control their sleep and to sleep at regular times, which means they often fail to wake, fully refreshed. In Fibromyalgia this leads to a cycle of sleep problems, fatigue and pain.

A link to CFS/ME on the NHS website

Arthritis (General)

There are over 100 types of Arthritis and diagnosing specific types is a difficult process. Difficult as it may be, it is also an essential process, as different types need different treatments. It is of course possible to have both conditions, at the same time. As part of a Fibromyalgia diagnoses Arthritis should be investigated. There are two main groups of Arthritis, Osteoarthritis and Inflammatory Arthritis.

Normally Osteoarthritis can be diagnosed by looking at the joints through examination, X-Ray or scans. The most common areas of investigation are usually the hands, feet and spine, as the more delicate joints, followed by load bearing joints like knees and hips. Osteoarthritis is often referred to as the “wear and tear” form of arthritis, as it is all about damage to the joints. As such it occurs more frequently the older we get. It can effect younger people, particularly those with a more active life, or with hobbies that put stress on the joints, such as dancing. So if your pain is worse in particular joints, it’s probably worth getting them looked at specifically, as part of the diagnostic process.

Inflammatory Arthritis is also diagnosed by looking at the joints through examination, X-Ray or Scans and by blood tests. Most types of inflammatory arthritis result in an increase of “inflammatory markers” in the blood. You may hear your Rheumatologist talking to you about the rheumatoid factor, erythrocyte sedimentation rate and similar blood markers. There are lots of different types of inflammatory arthritis and it is important that the correct form is diagnosed, as they can eat away parts of joints and cause permanent damage.

A link to Arthritis on the NHS website

Psoriatic Arthritis

I am including Psoriatic Arthritis as I have had to research the condition quite a bit. This is probably the most likely form of Arthritis that I would suffer from. The reason for this is because I suffer from Psorasis. I describe Psorasis in three types, even though I am not sure if it is 100% medically accurate. Type 1 is skin Psorasis, a quick google image search will bring up various pictures of what Psorasis looks like on the skin. Type 2 Psorasis is in the nails and manifests itself as pitting in the nails and can give the nail a yellowish appearance, where it seperates from the skin. It also causes layering underneath the nail and it appears as if the nail is splitting into several layers. I suffer from both Type 1 and Type 2 Psorasis and I class Psoriatic Arthritis as Type 3.

Psoriatic arthritis can, apparently, develop in up to 30% of people with chronic psoriasis. It is a form of inflammatory arthritis bu is thought to be a seronegative spondylarthropathy that occurs most frequently in people with tissue type HLA-B27. Psoriatic arthritis can take a number of forms and can appear to be very similar to rheumatoid arthritis but in a small number of cases.

There are commonly five types of psoriatic arthritis: Asymmetric, symmetric, arthritis mutilans, spondylitis and distal interphalangeal predominant. Asymmetric is, apparently, the most common form affecting around 70% of cases. It is usually mild and affects a few joints but not the same ones on each side of the body. Symmetric is affects joints on both sides of the body and is similar to rheumatoid arthritis. It affects about 25% of cases, 50% of which is disabling. Arthritis mutilans occurs in a small number of cases but is severe, deforming and destructive.

Spondylitis occurs in about 5% of cases. It can be associated with sacroiliitis but not always. It has a male predominance. It is characterised by stiffness in the spine or neck. Since the the normal test for psoriatic arthritis is to X-ray for signs of scaroiliitis (involvement of the sacrum) it may not be detected if it is confined to the neck and upper spine. It can involve the antlantoaxial joint at the top of the spine and cause some neurological problems. This can cause some of the symptoms associated with fibromyalgia. Distal Interphalageal again this can occur in around 5% of cases. It affects the joints near the ends of the fingers and toes.

In my case I was concerned with the possibility of spondylitis and requested this to be investigated through x-ray/MRI scan as this was not included under the NHS Pathways to diagnosis for Psoriatic arthritis.

A link to a section about Psoriasis on the NHS website that describes Psoriatic Arthritis

Ankylosing Spondylitis

Ankylosing spondylitis is a chronic inflammatory rheumatic disease of unknown cause and varying clinical presentation. The principal features (not all of which are present at onset, or in all people) are: Insidious onset (over a period of at least 3 months, and often several years) usually beginning in late adolescence or early adulthood. Inflammatory low back pain, (pain and stiffness worse at night and in the morning). Inflammation of the spinal joints and the junction (enthesis) of the intervertebral spinal ligaments and vertebrae, leading (after many years) to ankylosis (i.e. fusion from fibrosis and calcification). Inflammation of the sacroiliac joints (on X-ray or other radiological imaging), which presents as alternating buttock pain. Enthesitis (inflammation of the sites where tendons and ligaments attach to bone), costochondritis (inflammation where cartilage joins the ribs), and epicondylitis (inflammation of an epicondyle of bone). Arthritis of peripheral joints, usually involving the large joints of the lower limbs, or asymmetric arthritis of peripheral joints. Fatigue.

The features of Ankylosing Spondylitis are very clinical in their description but I have left the technical terminology in the paragraph above as I found it helped me when discussing Ankylosing Spondylitis with my Rheumatologist. I will again mention here my word of caution. In 95% of cases of Spondylitis in the spine, it effects the sacrum (lower spine) and as such when looking for a diagnosis under the NHS pathways to diagnosis this becomes the test for Psoriatic Arthritis in the spine. However I have found out that 5% of cases involve Spondylitis being present in the top of the spine. The NHS do not perform routine tests for this because it is unlikely. Therefore if you suspect Spondylitis it may be worth discussing this with your consultant, who may decide to do an X-Ray of the top of the spine, so it can be ruled out.

A link to Ankylosing Spondylitis on the NHS website


Diabetes is a chronic condition marked by abnormally high levels of sugar (glucose) in the blood. People with diabetes either do not produce enough insulin (a hormone that is needed to convert sugar, starches and other food into energy needed for daily life) or cannot use the insulin that their bodies produce and as a result, glucose builds up in the bloodstream. There are two types of Diabetes and both can have symptoms very similar to Fibromyalgia, in fact it can be one of the first things a doctor tests for, when you initially present.

Type 1: Type 1 diabetes can occur at any age, but it usually starts in people younger than 30. Symptoms are usually severe and occur rapidly. They include, increased thirst, increased urination, weight loss despite increased appetite, nausea, vomiting, abdominal pain, fatigue, Absence of menstruation.

Type 2: People with type 2 diabetes often have no symptoms, and their condition is detected only when a routine exam reveals high levels of glucose in their blood. Symptoms can occur and some can be very similar to Fibromyalgia, these are numbness or burning sensation of the feet, ankles, and legs. Blurred or poor vision, impotence, fatigue, poor wound healing, excessive urination and thirst, yeast infections and whole body itching.

A link to Diabetes on the NHS website

Systemic Lupus Erythematosus (SLE or Lupus)

Again symptoms are similar to Fibromyalgia, particularly making it difficult to get up each morning. In Lupus the body reacts to certain proteins which it thinks are foreign. This results in inflammation to the joints but also to internal organs. “Butterfly rash” a rash across the cheeks occurs in 15 to 20 percent of cases. There may be unusual sensitivity to sunligh,t that causes rashes or other illnesses. Hair loss, discolouration of the fingers and toes when exposed to cold (Raynauds Phenomenon), can occur. Half of people with Lupus have Kidney Disease. Blood disorders can cause anaemia and blood clots. Chest pain from heart and lung inflammation can happen and seizures or strokes can occur.

Blood tests are used to diagnose, especially the ANA (antinuclear antibody) test, can help with about 95% of active cases of Lupus having positive ANA blood tests, although not everyone with a positive test has Lupus. Again examination by a doctor and discussion of symptoms and history can help to indicate Lupus, which is important as the proper treatment is essential to manage this condition.

A link to Lupus on the NHS website

Polymyalgia Rheumatica

Indications can include a sudden onset of severe pain and stiffness, low fever and weight loss. This condition differs from Fibromyalgia because it includes inflammation where generally Fibromyalgia does not cause inflammation, unless a secondary condition is present. Inflammation and swelling sometimes occur in other soft tissues of the body. For example, tendons may become inflamed (tenosynovitis), your hands or feet may become slightly swollen, and some joints may become slightly swollen. No blood test is 100% reliable for PMR. However, blood tests called the erythrocyte sedimentation rate (ESR) test and the C-reactive protein (CRP) test can detect if there is inflammation in your body from various diseases. If either of these blood tests shows a high level of inflammation, and you have the typical symptoms, then this usually confirms the diagnosis of PMR.

A link to Polymyalgia Rheumatica on the NHS website


Hepatitis is a serious inflammation of the liver, usually due to a virus. It can also be caused by an overactive immune system, and from drugs, alcoholism, chemicals, and environmental toxins. It’s symptoms, particularly in people with chronic hepatitis, do not always have the symptoms of acute hepatitis. Some people with hepatitis C feel only mild ongoing fatigue and, perhaps, whole body itching. There are five types of Hepatitis (A, B, C, D & E) although D and E are rare.

Symptoms of Hepatitis include flu like symptoms including fever, as well as aching or painful muscles and joints. Jaundice (yellow discoloration of both your skin and the whites of your eyes), abdominal pain, fatigue, weight loss, loss of appetite, nausea, vomiting, dark urine, colourless stool, diarrhoea, body itching, mild anaemia and a enlarged, tender liver. Diagnosis is by a blood test.

A link to Hepatitis on the NHS website

Lyme disease

Lyme disease is an infection that derives from a tick bite. The disease has a variety of symptoms, including changes affecting the skin, heart, joints and nervous system. It is also known as borrelia or borreliosis. Simply seeing a tick somewhere on your body does not mean that you have contracted Lyme disease. Symptoms include a red spot around the location of the tick’s bite. The spot will gradually grow bigger, often with a pale area in the middle. This symptom is called erythema migrans and normally appears one to four weeks after a bite and they can also appear at other places on the body where the tick has not bitten. Some patients with Lyme disease feel like they have caught flu, the symptoms may be drowsiness, headaches, mild fever, joint pains, muscle pains and swollen lymph glands. I am also aware of theories suggesting Lyme disease can trigger Fibromyalgia, although I am not aware of any specific evidence supporting this.

A link to Lyme disease on the NHS website

Ehlers-Danlos Syndrome (EDS)

EDS is a genetic connective tissue condition characterised by skin extensibility, joint hypermobility and tissue fragility. There are six different types of EDS and they are classified according to signs and symptoms. Diagnosis is based on the presenting symptoms and family history of a patient. Many EDS sufferers, however, do not fit conveniently into the definition of a specific type, and are frequently misdiagnosed.

Stretchy skin characterises all types of EDS, except for the Vascular Type (type lV), which has noticeably translucent skin with visible veins. Joints are hypermobile due to the extra elasticity of the ligaments resulting from the collagen abnormality. This makes them susceptible to subluxation and dislocation. This often occurs without significant trauma as would be necessary to cause dislocation in somebody who does not have EDS. (Although those with the Vascular Type do not generally exhibit joint laxity) Easy bruising accompanies most forms of EDS. Mitral Valve Prolapse is quite common and should be diagnosed by echocardiography, CT or MRI.

A link to EDS on the NHS website

Behçet’s disease

Behçet’s disease is a complex multi-system disorder of unknown aetiology characteristically presenting with recurrent oral ulcers. It is presumed to be an autoimmune disease and includes involvement of the mucocutaneous, ocular, cardiovascular, renal, gastrointestinal, pulmonary, vascular, musculoskeletal, urological and central nervous systems. However it is important to note that Behçet’s disease is quite rare (Prevalence is 0.3-6.6 cases per 100,000 population and prevalence is highest in the Middle East, China and Japan).

The main feature of this disease is recurrent Oral and Genital Ulceration, (at least 3 episodes of oral ulceration must occur in a 12-month period). These ulcers are painful on the genitals and usually heal with scarring. Ophthalmic (eye) lesions can occur, including anterior or posterior uveitis, hypopyon, or retinal vasculitis. Blood tests will be used and a full blood count may show mild anaemia and raised white cell count. Non-specific inflammatory markers: CRP, ESR, complement and acute-phase reactants may all be elevated during an acute attack. Other methods of diagnoses include skin trauma tests (needleprick), examination of synovial fluid, examination of cerebrospinal fluid and skin biopsies.

A link to Behçet’s disease on the NHS website

Addison’s disease

For me this was my annual “Oh, maybe you have this not Fibromyalgia” theory for 2013. Unfortunately (in a bizarre way) the tests came back negative. I say this as Addison’s has a specific test and is manageable with medication which is two things it does not have in common with Fibromyalgia, however when you read into it you find that there are many things that Addison’s and Fibromyalgia do have in common, especially the symptoms.

Addison’s disease (also known as primary adrenal insufficiency or hypoadrenalism) is a rare (14 in a 100,000 in the UK) disorder of the adrenal glands. It affects the production of two hormones – cortisol and aldosterone – which help to regulate blood pressure. At first, the symptoms of Addison’s disease are similar to the more common health conditions such as depression or flu. These may progress to dizziness, fainting, cramps, exhaustion and increasing skin pigmentation. It is thought that stress such as an illness or accident can also trigger these symptoms, or cause them to get worse.

The symptoms of Addison’s are broken down into two groups Initial and Progressive:

Initial symptoms include fatigue (lack of energy or motivation), lethargy (abnormal drowsiness or tiredness), muscle weakness, low mood (mild depression) or irritability, loss of appetite and, unintentional weight loss, low blood pressure (hypotension), the need to urinate frequently, increased thirst, craving for salty foods and hypoglycaemia (low blood sugar)

Progressive symptoms include the initial symptoms becoming more severe or more frequent and in addition low blood pressure when you stand up (postural or orthostatic hypotension), dizziness and fainting, feeling like you are going to be sick (nausea), vomiting and diarrhoea, abdominal, joint, or back pain, muscle cramps, chronic exhaustion, which may cause depression or tearfulness, brownish discolouration of the skin, lips and gums (hyperpigmentation), particularly in the creases on your palms, on scars or on pressure points, such as your knuckles or knees. In women, a reduced libido (a lack of interest in sex). Symptoms such as sweating and, very occasionally, psychosis occur but are unusual. Some women may also have irregular periods or miss some periods completely.

It is important to note that if Addison’s is left untreated it can lead to an Adrenal Crisis. Now these can be fatal so it is important to know the signs, click here and scroll down to the “Adrenal Crisis” heading on the NHS website. Addison’s can be managed with medication and most people can lead a normal life if it is controlled properly. If Addison’s Disease is suspected you will probably be given a Short Synacthen Test (Click here to read my blog post about my Short Synacthen Test). This test involves a control blood test, then an inter-muscular injection of cortisol followed by another blood test at a specified time, normally 30 or 60 minutes later. This test is to find out how your body responds to the cortisol injection and from this a diagnosis can start to be formed. If this is positive you may then require a (long) Synacthen Test where more blood is drawn at a number of specified times after the cortisol injection. This allows doctors to analyse your bodies response to the cortisol in more detail. In terms of similar conditions to Fibromyalgia it is important to note that Addison’s Disease is rare, however it can be fatal if not treated, but there is a specific test for it and your prospects in the future are good as normally it can be successfully managed.

Final thought

Fibromyalgia is a difficult condition to diagnose and there will be occasions of misdiagnosis due to human error, however most, or at least the most serious instances of misdiagnosis are rare. It can be quite natural for people with Fibromyalgia to search for alternative conditions and even think they may have them, as Fibromyalgia is very hard to live with and there is no definitive test for it. In all cases you should discuss these feelings with your doctor or consultant, most will be more than happy to check for these conditions if you bring them up and you may find you have already been tested for them anyway.

I have spent a lot of my time looking into alternative diagnosis myself and can offer some advice. If you have signs of swelling or inflammation, changes in bowel habits, problems with abdominal pain or localised pain in a specific area or joint, then go and speak to your doctor. Don’t just put new symptoms down to Fibromyalgia but rather raise them with your doctor. The aim is to get a healthy balance between a hypercondriac and ignoring everything.

This guide is not intended to be a diagnostics tool but gives information, often in summary, of conditions whose symptoms can appear very much like Fibromyalgia. If you think you may have one of these conditions then speak to your doctor. Also do not start to take any new medication or treatment unless your doctor prescribes it, or refers you for it. This guide is not written by a doctor, checked by a doctor or endorsed by a doctor, so if it gets you thinking, then the least you can do, is speak to a doctor.