Features

• Uric acid is the final metabolic product of a DNA constituent called purine. Uric acid can be a problematic substance because of its low solubility, and the fact that humans do not have the enzyme uricase, which converts it into a more soluble compound called allantoin.
  
  

Causes

• Three conditions contribute to the formation of uric acid stones: a low urine pH (high acidity); a high urinary uric acid concentration, and a lack of enzymes that normally inhibit stone formation. Uric acid stones are most frequent in the following cases: dehydration; chemotherapy; patients with gout, some blood cell diseases, and rapid weight loss.
  
  Specific causes include: purine enzyme defects, blood cell disorders, hemolytic anemia, certain drugs, excessive dietary purine intake (e.g., beer), kidney disorders, and dehydration.
  
  

Signs & Symptoms

• The main symptoms of uric acid stones is a severe pain that may stop as suddenly as it comes. The pain might be located in the abdominal area, either side of the back, the groin area, or testicles.
  Additional symptoms may include: blood in the urine; abnormal urine color, nausea, vomiting, fever, and chills. Outside of the kidney, uric acid crystals can also cause severe joint or tissue pain.
  
  

Medical Treatment

• Bicarbonate or citrate can sometimes help dissolve uric acid stones by making the urine less acid. Additional options include: Allopurinol (Zyloprim), shock-wave therapy and surgery. Surgery is uncommon, unless a stone resists other treatment methods, is too large to pass on its own, is growing, obstructing, or contributing to kidney infection or damage
  
  

Home Treatment

• To reduce the size of uric acid stones or prevent the formation of new ones, two measures are important: reducing dietary purine, especially in the form of animal protein, and drinking enough fluid to maintain a urine output of 2 to 3 L per day. Six to eight glasses of water should be the minimum daily intake. Pain relievers, such as Ibuprofen, may help control the pain of passing the stones.
  
  

Complications

• Kidney stones, including uric acid stones, carry a risk of complications. Some possible complications are: recurrence, renal failure, infection, obstruction of the urinary tract, pallor, and insomnia.