A disease in which the body's tissues are attacked by its own immune system.  There are many autoimmune diseases including lupus, rheumatoid arthritis, diabetes etc.
Autoimmune Disease Checklist:
A Handy List of Symptoms That Can Point to Possible Autoimmune Conditions, to Bring to the Doctor 

by Mary Shomon

The following is a partial checklist of frequently-noticed symptoms of the most common autoimmune conditions. This list is by no means exhaustive, but it covers many of the common autoimmune symptoms and conditions. Carefully filling out this checklist and taking it to your doctor can be an important first step in getting appropriate testing and the right medical diagnosis.

Fever / Body Temperature

_____ Elevated fever, higher body temperature - Lupus, Graves' Disease/Hyperthyroidism, Celiac Disease/Gluten Intolerance/Irritable Bowel Syndrome
_____ Feeling cold when others feel hot -- Hashimoto's Hypothyroidism
_____ Feeling hot when others feel cold -- Graves' Disease/Hyperthyroidism
_____ Low body temperature -- Hashimoto's Hypothyroidism

Hair

_____ Hair loss, round bald patches on the scalp -- Alopecia Areata
_____ Hair loss, loss of facial and scalp hair -- Alopecia Totalis, Hashimoto's Hypothyroidism, Graves' Disease/Hyperthyroidism, Lupus
_____ Male patterned baldness -- Hashimoto's Hypothyroidism, Graves' Disease/Hyperthyroidism, Polycystic Ovary Syndrome (PCOS)
_____ Excess hair growth on the face faces, necks, chests, abdomens, and thighs, in women - Cushing's Disease, Polycystic Ovary Syndrome (PCOS)
_____ Loss of hair in outer eyebrow -- Hashimoto's Hypothyroidism
_____ Hair is rough, coarse dry, breaking, brittle - Hashimoto's Hypothyroidism, Graves' Disease/Hyperthyroidism

Skin

_____ Hyperpigmentation, or dark tanning in skin -- Addison's Disease
_____ Painful skin rash, called dermatitis herpetiformis -- Celiac Disease/Gluten Intolerance/Irritable Bowel Syndrome
_____ Fragile thin skin - Cushing's Disease
_____ Skin that bruises easily - Cushing's Disease
_____ Acne -- Polycystic Ovary Syndrome (PCOS), Hashimoto's Hypothyroidism
_____ Skin rashes, especially "butterfly rash" on the nose and cheeks -- Lupus
_____ Sun sensitivity -- Lupus
_____ Skin thickening -- Scleroderma
_____ Skin ulcers on the fingers -- Scleroderma

Eyes

_____ Dry eyes -- Sjogren's Syndrome, Hashimoto's Hypothyroidism, Graves' Disease/Hyperthyroidism
_____ Blurred vision -- Sjogren's Syndrome, Hashimoto's Hypothyroidism, Graves' Disease/Hyperthyroidism, Multiple Sclerosis
_____ Eye discomfort or pain -- Sjogren's Syndrome, Hashimoto's Hypothyroidism, Graves' Disease/Hyperthyroidism, Multiple Sclerosis
_____ Nystagmus or jerking, rapid involuntary eye movement -- Multiple Sclerosis, Hashimoto's Hypothyroidism
_____ Optic neuritis, inflammation of the nerves in the eye -- Multiple Sclerosis
_____ Unclear or double vision -- Graves' Disease/Hyperthyroidism, Multiple Sclerosis

Throat, Neck, Voice, Mouth

_____ Dry mouth -- Sjogren's Syndrome
_____ Hoarseness, husky or gravelly voice -- Sjogren's Syndrome, Hashimoto's Hypothyroidism, Graves' Disease/Hyperthyroidism
_____ Difficulty in swallowing -- Sjogren's Syndrome, Hashimoto's Hypothyroidism, Graves' Disease/Hyperthyroidism
_____ Mouth and nose sores -- Lupus
_____ Pale sores inside the mouth, called aphthus ulcers -- Celiac Disease/Gluten Intolerance/Irritable Bowel Syndrome
_____ Fullness or pressure, choking sensation in throat, lump in the neck -- Hashimoto's Hypothyroidism, Graves' Disease/Hyperthyroidism

Fatigue, Sleep

_____ Chronic fatigue - Addison's Disease, Hashimoto's Hypothyroidism, Celiac Disease/Gluten Intolerance/Irritable Bowel Syndrome, Chronic Fatigue Syndrome, Sjogren's Syndrome, Lupus, Insulin-Dependent Type 1 Diabetes
_____ Insomnia -- Graves' Disease/Hyperthyroidism
_____ Exhaustion after minimal effort or exercise - Fibromyalgia, Hashimoto's Hypothyroidism, Graves' Disease/Hyperthyroidism, Chronic Fatigue Syndrome, Sjogren's Syndrome, Lupus

Muscles, Joints, Tendons

_____ Pain and tenderness throughout the body - Fibromyalgia, Chronic Fatigue Syndrome, Lupus, Sjogren's Syndrome
_____ Muscle weakness -- Addison's Disease, Hashimoto's Hypothyroidism, Graves' Disease/Hyperthyroidism, Fibromyalgia, Chronic Fatigue Syndrome
_____ Joint Stiffness - Scleroderma, Rheumatoid Arthritis, Fibromyalgia
_____ Bone, joint and muscle aches, inflammation, and pains -- Celiac Disease/Gluten Intolerance/Irritable Bowel Syndrome, Cushing's Disease, Lupus, Sjogren's Syndrome, Rheumatoid Arthritis
_____ Backaches, unexplained rib and spinal column fractures- Cushing's Disease
_____ Deformed joints - Rheumatoid Arthritis
_____ Carpal-tunnel syndrome / tendinitis -- Hashimoto's Hypothyroidism

Hands and Feet

_____ Raynaud's phenomenon (extreme sensitivity to cold in the hands and feet) -- Lupus, Hashimoto's Hypothyroidism, Graves' Disease/Hyperthyroidism
_____ Swelling in hands and feet - Lupus, Scleroderma, Hashimoto's Hypothyroidism

Weight Changes

_____ Weight loss -- Addison's Disease, Graves' Disease/Hyperthyroidism, Celiac Disease/Gluten Intolerance/Irritable Bowel Syndrome, Lupus, Insulin-Dependent Type 1 Diabetes
_____ Weight Gain - Cushing's Disease, Graves' Disease/Hyperthyroidism, Hashimoto's Hypothyroidism, Chronic Fatigue Syndrome, Celiac Disease/Gluten Intolerance/Irritable Bowel Syndrome
_____ Weight gain in upper body, abdomen - Cushing's Disease, Polycystic Ovary Syndrome (PCOS)
_____ Rounded or puffy face - Cushing's Disease, Hashimoto's Hypothyroidism
_____ Increased fat around the neck - Cushing's Disease
_____ Thinning arms and legs - Cushing's Disease

Digestion, Gastrointestinal

_____ Nausea, vomiting, or diarrhea -- Addison's Disease, Graves' Disease/Hyperthyroidism, Celiac Disease/Gluten Intolerance/Irritable Bowel Syndrome, Scleroderma, Insulin-Dependent Type 1 Diabetes
_____ Recurring abdominal bloating and pain -- Celiac Disease/Gluten Intolerance/Irritable Bowel Syndrome
_____ Pale, foul-smelling stool -- Celiac Disease/Gluten Intolerance/Irritable Bowel Syndrome
_____ Gas -- Celiac Disease/Gluten Intolerance/Irritable Bowel Syndrome
_____ Increased urination -- Insulin-Dependent Type 1 Diabetes
_____ Constipation - Hashimoto's Hypothyroidism

Pulse/Blood Pressure

_____ Low blood pressure -- Addison's Disease, Hashimoto's Hypothyroidism
_____ High blood pressure- Cushing's Disease, Graves' Disease/Hyperthyroidism, Hashimoto's Hypothyroidism, Polycystic Ovary Syndrome (PCOS)
_____ Slow pulse -- Hashimoto's Hypothyroidism
_____ Fast Pulse -- Graves' Disease/Hyperthyroidism

Mood, Thinking

_____ Irritability, anxiety and depression -- Addison's Disease, Celiac Disease/Gluten Intolerance/Irritable Bowel Syndrome, Cushing's Disease, Graves' Disease/Hyperthyroidism, Hashimoto's Hypothyroidism
_____ "Brain Fog," difficulty concentrating, forgetfulness -- Graves' Disease/Hyperthyroidism, Hashimoto's Hypothyroidism, Fibromyalgia, Chronic Fatigue Syndrome

Balance, Coordination, Neurological Symptoms

_____ Lack of coordination or unsteady gait -- Multiple Sclerosis
_____ Dizziness, vertigo -- Multiple Sclerosis, Hashimoto's Hypothyroidism
_____ Numbness, weakness, tingling or paralysis in one or more limbs - Multiple Sclerosis, Insulin-Dependent Type 1 Diabetes
_____ Tremor -- Multiple Sclerosis, Graves' Disease/Hyperthyroidism

Food/Drink & Cravings

_____ Craving of salty foods -- Addison's Disease
_____ Increased thirst -- Insulin-Dependent Type 1 Diabetes
_____ Loss of appetite -- Addison's Disease, Graves' Disease/Hyperthyroidism

Menstruation/Gynecological - Women

_____ Irregular or absent menstrual periods -- Addison's Disease, Graves' Disease/Hyperthyroidism, Hashimoto's Hypothyroidism, Celiac Disease/Gluten Intolerance/Irritable Bowel Syndrome, Cushing's Disease, Polycystic Ovary Syndrome (PCOS)
_____ Cysts on Ovaries -- Polycystic Ovary Syndrome (PCOS)

Fertility and Sex Drive, Pregnancy

_____ Infertility or decreased fertility in women -- Graves' Disease/Hyperthyroidism, Hashimoto's Hypothyroidism, Polycystic Ovary Syndrome (PCOS)
_____ Decreased fertility in men- Cushing's Disease
_____ Reduced sex drive - Cushing's Disease, Graves' Disease/Hyperthyroidism, Hashimoto's Hypothyroidism
_____ Recurrent miscarriage - Graves' Disease/Hyperthyroidism, Hashimoto's Hypothyroidism

Breathing

_____ Increase in snoring -- Hashimoto's Hypothyroidism
_____ Shortness of breath and tightness in the chest -- Hashimoto's Hypothyroidism

Especially in Children

_____ Delayed growth in children, failure to thrive in infants -- Celiac Disease/Gluten Intolerance/Irritable Bowel Syndrome, Cushing's Disease, Hashimoto's Hypothyroidism

Blood Changes

_____ Unexplained anemia (low count of red blood cells) -- Celiac Disease/Gluten Intolerance/Irritable Bowel Syndrome
_____ High cholesterol levels -- Hashimoto's Hypothyroidism

Blood Sugar Changes

_____ Hypoglycemia/low blood sugar -- Addison's Disease, Hashimoto's Hypothyroidism
_____ High blood sugar- Cushing's Disease, Polycystic Ovary Syndrome (PCOS)