Uric acid - blood

[Herbalist Dr MziziMkavu]

Uric acid is a chemical created when the body breaks down substances called purines. Purines are found in some foods and drinks, such as liver, anchovies, mackerel, dried beans and peas, beer, and wine.

Most uric acid dissolves in blood and travels to the kidneys, where it passes out in urine. If your body produces too much uric acid or doesn't remove enough if it, you can get sick. High levels of uric acid in the body is called hyperuricemia.
This test checks to see how much uric acid you have in your blood.


How the Test is Performed

A blood sample is needed. For information on how this is done, see: Venipuncture

How to Prepare for the Test

You should not eat or drink anything for 4 hours before the test unless told otherwise. Your doctor may also tell you to stop taking any drugs that may affect the test results. Never stop taking any medicine without talking to your doctor.
Drugs that can increase the level of uric acid in your body include:

• Alcohol
• Ascorbic acid
• Aspirin
• Caffeine
• Cisplatin
• Diazoxide
• Diuretics
• Epinephrine
• Ethambutol
• Levodopa
• Methyldopa
• Nicotinic acid
• Phenothiazines
• Theophylline

Drugs that can decrease the level of uric acid in your body include:

• Allopurinol
• Azathioprine
• Clofibrate
• Corticosteroids
• Estrogen
• Febuxostat
• Glucose
• Guaifenesin
• Mannitol
• Probenecid
• Warfarin

Why the Test is Performed

This test is done to see if you have high levels of uric acid in your blood. High levels of uric acid can cause goutor kidney disease.
Your doctor may also order this test if you have had or are about to have certain types of chemotherapy. Rapid weight loss, which may occur with such treatments, can increase the amount of uric acid in your blood.

Normal Results

Normal values range between 3.5 and 7.2 mg/dL.
Note: Normal values may vary slightly from laboratory to laboratory.
What Abnormal Results Mean

Greater-than-normal levels of uric acid (hyperuricemia) may be due to:

• Acidosis
• Alcoholism
• Diabetes
• Gout
• Hypoparathyroidism
• Lead poisoning
• Leukemia
• Nephrolithiasis
• Polycythemia vera
• Renal failure
• Toxemia of pregnancy
• Purine-rich diet
• Excessive exercise
• Chemotherapy-related side effects

Lower-than-normal levels of uric acid may be due to:

• Fanconi syndrome
• Wilson's disease
• Syndrome of inappropriate antidiuretic hormone (SIADH) secretion
• Low purine diet

Additional conditions under which the test may be performed:

• Chronic gouty arthritis
• Injury of the kidney and ureter

References

Curhan GC, Mitch WE. Diet and kidney disease. In: Brenner BM, eds. Brenner and Rector’s The Kidney. 8th ed. Philadelphia, Pa: Saunders Elsevier; 2008:chap 53.
Update Date: 5/30/2011

Updated by: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

Source: Uric acid - blood : MedlinePlus Medical Encyclopedia

 

[Herbalist Dr MziziMkavu]

Uric acid - urine

Uric acid is a chemical created when the body breaks down substances called purines. Purines are found in some foods and drinks, such as liver, anchovies, mackerel, dried beans and peas, beer, and wine. Purines are also a part of normal body substances, such as DNA.

Most uric acid dissolves in blood and travels to the kidneys, where it passes out in urine. If your body produces too much uric acid or doesn't remove enough of it, you may get sick. High levels of uric acid in the body is called hyperuricemia.
This test checks to see how much uric acid you have in your urine.


How the Test is Performed

A 24-hour urine sample is needed. See: 24-hour urine collection.

How to Prepare for the Test

Your doctor may tell you to stop taking any drugs that may affect the test results. For example, high levels of vitamin C and dyes used during certain x-rays may cause incorrect results.
Drugs that can interfere with test results include:

• Alcohol
• Allopurinol
• Anti-inflammatory drugs (such as ibuprofen)
• Salicylates (including aspirin)
• Thiazide diuretics
• Probenecid

This list may not be all-inclusive.

How the Test Will Feel

The test involves only normal urination, and there is no discomfort.
Why the Test is Performed

This test may be done to diagnose the cause of kidney stones. It may also be used to monitor people with gout, since many of these patients develop uric acid kidney stones.

Normal Results

Normal values range from 250 to 750 milligrams per 24 hours.
Note: Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.

What Abnormal Results Mean

Higher than normal uric acid levels in the urine may be due to:

• Cancers that have spread (metastasized)
• Disorders that affect the bone marrow or certain white blood cells
• High-purine diet
• Gout
• Rhabdomyolysis
• Lesch-Nyhan syndrome
• Fanconi syndrome

Lower than normal uric acid levels in the urine may be due to:

• Long-term alcohol use
• Chronic glomerulonephritis
• Lead poisoning

References

McPherson RA, Pincus MR. Henry's Clinical Diagnosis and Management by Laboratory Methods. 21st ed. St. Louis, Mo: WB Saunders; 2006.
Bazari H. Approach to the patient with renal disease. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 115.
Update Date: 8/10/2009

Updated by: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

Uric acid - urine: MedlinePlus Medical Encyclopedia

 

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