Antinuclear antibodies (ANA) target normal proteins within cells, causing cell destruction and damaging healthy body tissues. The ANA blood test reveals the presence of antinuclear antibodies in the blood. While a positive ANA does not always indicate the presence of disease, several diseases cause positive ANA test results and cause similar symptoms.

Lupus

Lupus causes pain, inflammation and damage to the organs. This condition affects the skin, kidneys, joints and other parts of the body. People with lupus experience periods of severe symptoms (flares), followed by remission from those symptoms. The American Association for Clinical Chemistry reports that the homogeneous and outline antinuclear antibody patterns indicate the presence of lupus.

Scleroderma

Scleroderma causes the hardening and tightening of the skin and connective tissues. This condition occurs when the body produces too much collagen. Scleroderma can cause scarring of the lungs, kidneys and heart tissue, increasing the risk for serious conditions such as high blood pressure and abnormal heart rhythm. Scleroderma can also cause dental complications and contribute to erectile dysfunction, according to the Mayo Clinic 2.

Sjogren's Syndrome

Like other diseases that cause positive ANA test results, Sjogren’s syndrome is an autoimmune disorder with an unknown cause. The American College of Rheumatology estimates that 400,000 to 3.1 million adults have this condition 3.

Mixed Connective Tissue Disease

Mixed connective tissue disease has features of systemic sclerosis, systemic lupus and polymyositis. This condition causes joint pain, weakness, skin abnormalities and damage to the internal organs. Mixed connective tissue disease also causes Raynaud’s syndrome, which causes the fingers to get pale and numb when exposed to cold temperatures. The speckled antinuclear antibody pattern indicates the possibility that mixed connective tissue disease is present.

Rheumatoid Arthritis

Rheumatoid arthritis occurs in three stages. Stage one results in swelling of the lining of the joints. Stage two causes thickening of the joint lining. Stage three results in the release of enzymes that digest cartilage and bone. This causes pain, loss of movement and loss of joint shape. Symptoms of rheumatoid arthritis include:

• stiffness
  
• weakness
  
• fatigue
  
• flu-like symptoms
  
• muscle pain
  
• loss of appetite

Dermatomyositis

Dermatomyositis causes persistent muscle inflammation and muscle weakness. These symptoms follow a skin rash that appears patchy, with bluish-red discoloration of the skin. This rash develops on the muscles used to control the joints and on the eyelids. No cure exists for dermatomyositis, but physical therapy, rest, heat therapy and exercise treat the symptoms of the disease.

Raynaud's Disease

Raynaud’s disease causes the arteries to narrow, reducing blood flow to the toes and fingers. This disorder can also affect the nipples, lips, nose and ears. Primary Raynaud’s occurs without a known cause. Secondary Raynaud’s occurs as the result of another condition. During a Raynaud’s attack, reduced blood flow causes the skin to turn white and then blue. When blood flow returns, Raynaud's sufferers may experience numbness, tingling, burning or throbbing.