1. Hashimoto's thyroiditis
   Vasculitis
2. Addison's disease
   Kawasaki disease

Symptoms of Addison's disease usually include weight loss, stomach pain and dehydration. Treatment involves replacing the hormones that are not present with something like an oral steroid.

1. Stiff person syndrome
   Type 1 diabetes
2. Multiple sclerosis
   Goodpasture's syndrome

Multiple sclerosis is a chronic condition that affects the brain and spinal cord. The myelin sheath is damaged, and that results in faulty nerve fiber conduction, which can lead to nerve death. The symptoms can range from muscle weakness to lack of balance, memory issues and more.

1. Susac's Syndrome
   Crohn's disease
2. Cogan syndrome
   Lambert-Eaton syndrome

Susac's syndrome sounds simple at first; just some blocked blood vessels. But the symptoms that can result are actually quite unusual. Though rare, some symptoms can include slurred speech, confusion, paranoia, and more.

1. Pernicious anemia
   Scleritis
2. Narcolepsy
   Stiff person syndrome

Narcolepsy is a chronic condition affecting the brain that results in completely unpredictable sleep attacks. Someone with narcolepsy doesn't sleep more than someone who doesn't have the condition, and it can occur at inopportune moments during any waking activity.

1. Amyloidosis
   Crohn's disease
2. Rheumatoid arthritis
   Lupus

There's a protein that can be formed in your bone marrow called amyloid that can build up and deposit in tissue throughout your body. The symptoms depend on what part of the body has the amyloid build-up, but it can go pretty much anywhere, from your tongue to your nerves to your heart.

1. CREST syndrome
   Chagas
2. Grave's disease
   Lupus

Lupus is a very hard condition to properly diagnose because there are four kinds of lupus, and it's able to attack so many parts of the body with so many divergent symptoms, that it's often easily misdiagnosed as a series of other conditions.

1. Vasculitis
   Rheumatoid arthritis
2. Woods Black Norbury syndrome
   Lyme disease

Rheumatoid arthritis affects about 1.5 million Americans and results in severe joint pain and inflammation. Though the symptoms can affect numerous parts of the body, they're most often found in the fingers and wrists.

1. Retinopathy
   Legionnaire's disease
2. Pancreatitis
   Diabetes

Over 1 million Americans have Type 1 diabetes, and about 40,000 people are diagnosed every year. Unlike Type 2, which occurs later in life and is often associated with diet, Type 1 occurs earlier and is often called juvenile diabetes. Your immune system attacks your pancreas and renders it unable to produce the insulin needed to regulate blood glucose.

1. Psoriasis
   Vitiligo
2. Scabies
   Eczema

Vitiligo is most easily recognizable for the visual symptoms associated with it. The melanocytes in the skin are where pigment is located. When they are destroyed, the skin loses pigment, which results in noticeable and irregular white patches on otherwise darker flesh. This was the condition Michael Jackson said he had.

1. Fibromyalgia
   Endometriosis
2. Lyme disease
   Peritonitis

Fibromyalgia has a string of symptoms that come along with it, including irritable bowel syndrome, anxiety and depression. It's often slow to be diagnosed because the symptoms are associated with other conditions as well.

1. Guillain-Barre Syndrome
   Chagas
2. Sarcoidosis
   Lyme disease

Lyme disease is contracted from deer ticks which will latch on and bite your flesh. If it's not treated it can cause issues with joint pain, memory loss, and shooting pains in the extremities like your arms and legs.

1. CREST syndrome
   Goodpasture syndrome
2. Endometriosis
   Evans Syndrome

Endometriosis affects up to 10% of all women, but the numbers are rather hard to pin down as some will never experience any definite symptoms of the disease. Others will experience intense pelvic pain and infertility.

1. Pernicious anemia
   Vasculitis
2. Hashimoto's thyroiditis
   Crohn's disease

Sometimes called chronic ileitis, Crohn's disease can affect any part of the digestive tract from the mouth on down, though typically it affects the small intestine. In severe cases, lengths of the intestine will have to be removed.

1. Pernicious anemia
   Stiff person syndrome
2. Sjogren's syndrome
   Scleritis

Pernicious anemia and anemia are similar but not the same condition. Anemia can be the result of simply not getting enough iron, blood loss, or poor absorption. Pernicious anemia is prompted by your intestine's inability to absorb vitamin B12.

1. Hashimoto's thyroiditis
   Guillain-Barre syndrome
2. Kawasaki disease
   Restless leg syndrome

Guillain-Barre syndrome is a fairly rare condition that only affects about 1 in 100,000 people. But it can be serious and even fatal in a number of cases if treatment isn't sought right away.

1. Psoriasis
   Achalasia
2. Grave's disease
   Raynaud's phenomenon

Psoriasis is one of the most common conditions in the world. It affects over 8 million Americans and over 125 million people worldwide. That means that about 2% to 3% of the population has it.

1. Mooren's ulcer
   Cogan syndrome
2. Scleritis
   Graves' disease

Graves' disease is characterized by hyperthyroidism which, unlike hypothyroidism, is an excess of hormones. It's also called toxic diffuse goiter and though it has a number of symptoms, one of the most obvious is bulging eyes.

1. Restless leg syndrome
   Hashimoto's thyroiditis
2. Optic neuritis
   Celiac disease

Hashimoto's thyroiditis is named for Hakaru Hashimoto, a physician from Japan who first identified the condition in 1912. It wasn't until 1957 that it was officially recognized as an autoimmune disease and also the first one ever that was organ-specific.

1. Pemphigus
   Hemolytic anemia
2. Vasculitis
   Evans syndrome

Vasculitis can have a number of causes, including an autoimmune deficiency. In that event, your blood vessels are attacked by your immune system, and it can affect arteries, veins, or more. Steroids are often the normal treatment.

1. Myasthenia Gravis
   Chagas disease
2. Lupus
   Addison's disease

Myasthenia gravis means "grave muscle weakness" in English and lives up to the name. Your immune system attacks your nerves and results in interference between nerves and muscles. This can affect the eyes and muscles in the face or any muscle in the body, causing them to fatigue quickly.

1. Scleroderma
   Multiple Sclerosis
2. Kawasaki disease
   Restless leg syndrome

It's extremely rare for someone over the age of 5 to contract Kawasaki disease. In general, it only affects a small percentage of children, except in Japan where it's about twice as common as it is anywhere else in the world.

1. Celiac disease
   Lupus
2. Goodpasture syndrome
   Addison's disease

The gluten-free push in modern eating is fueled, in part, by celiac disease. It's estimated that about 1 in 100 people actually have celiac disease, which is a remarkably high number compared to most other immune conditions.

1. Vitiligo
   Pemphigus
2. IBS
   Scleritis

Scleritis is an inflammation of the sclera, hence the name. This can actually be part of any number of other autoimmune conditions, including lupus and rheumatoid arthritis.

1. Blank's disease
   Ryer syndrome
2. Dressler's syndrome
   Stiff person syndrome

Not just a clever name, stiff person syndrome is a condition that can cause not just stiffness and rigidity but extreme pain and sensitivity to touch. It used to be called stiff-man syndrome, but no one likes a sexist disease.

1. Goodpasture syndrome
   Addison's disease
2. Lyme disease
   Vitiligo

Goodpasture's syndrome causes your body to create antiglomerular basement membrane antibodies which seek to destroy collagen in your lung or kidney tissue. This can lead to massive kidney failure and bleeding lungs.

1. Addison's disease
   Sarcoidosis
2. Multiple sclerosis
   Lupus

Sarcoidosis can affect any organ in the body and usually involves tiny granules forming in the tissue. It's not always something that requires treatment, but when it does, a steroid is the most common treatment.

1. Restless leg syndrome
   Pemphigus
2. Psoriasis
   Narcolepsy

Arguably one of the weirdest conditions in medicine, there's no definitive cause that anyone can point to for restless leg syndrome. Some medications and conditions can cause it temporarily, and some lifestyle changes can alleviate symptoms.

1. Fibrosing alveolitis
   Vasculitis
2. Scleritis
   Raynaud's phenomenon

The very bizarre Raynaud's phenomenon causes skin color changes as a result of exposure to cold temperatures or extreme emotions. Blood vessels spasm and block blood flow to areas of the body like fingers, ears, nose and toes. The skin will turn white and then blue due to a lack of blood flow.

1. Kawasaki disease
   Chagas disease
2. Vasculitis
   Juvenile arthritis

Chagas disease comes from a parasite commonly contracted from something known as kissing bugs. Initial symptoms are simple, like fever and swelling, but victims may suffer from serious heart ailments as much as 30 years later.

1. Lambert-Eaton syndrome
   Parsonage-Turner syndrome
2. Wilson's disease
   Vitiligo

Neuromuscular junctions are where your muscles and nerves connect, and that's where Lambert-Eaton syndrome has its effect. It causes extensive muscle weakness, trouble walking, dry mouth and difficulty breathing and swallowing.

1. Polymyositis
   Behcet's disease
2. Addison's disease
   CREST syndrome

CREST syndrome is an anagram that stands for calcinosis, Raynaud’s phenomenon, esophageal dysfunction, sclerodactyly, and telangiectasia. You can see why they choose to shorten it.

1. Discoid lupus
   Sjogren's syndrome
2. Schmidt syndrome
   Uveitis

Sjogren's syndrome seems to affect about 10 times as many women as it does men and usually sets in during middle age. The primary symptoms are dry mouth and dry eyes, though overall dry skin, cough, numbness and joint paint may also be present.

1. Evans syndrome
   Howard's disease
2. Balo disease
   Celiac disease

Evans syndrome is an extremely rare condition and must be diagnosed via a blood test. Symptoms are very much like anemia and can include lightheadedness, fatigue, pale skin and extensive bruising.

1. Devic's disease
   Psoriasis
2. Cogan's syndrome
   Optic neuritis

Like any autoimmune disease, Cogan's syndrome is the result of your immune system producing antibodies that attack healthy tissue, in this case, your eyes and ears. Steroids and immunosuppressants can be used to treat it. If it goes untreated, it could lead to deafness and blindness.

1. Addison's disease
   Dressler's syndrome
2. Grave's disease
   Takayasu's arteritis

Dressler's syndrome is thought to be an immune response that your body produces after your heart tissue gets damaged by something like a heart attack or surgery. It's less common these days now that heart attack treatment is better than it used to be.