Microhematuria, also called microscopic hematuria (both usually abbreviated as MH), is a medical condition in which urine contains small amounts of blood; the blood quantity is too low to change the color of the urine (otherwise, it is known as gross hematuria). While not dangerous in itself, it may be a symptom of kidney disease, such as IgA nephropathy or Sickle cell trait, which should be monitored by a doctor. The American Urological Association (AUA) recommends a definition of microscopic hematuria as three or more red blood cells per high-power microscopic field in urinary sediment from two of three properly collected urinalysis specimens.Microhematuria is usually asymptomatic, and there are medical guidelines on how to handle asymptomatic microhematuria (AMH) so as to avoid problems such as overtreatment or misdiagnosis. See also
Proteinuria
Hematuria
Myoglobinuria
Hemoglobinuria

References
External links
Cohen RA, Brown RS (2003). "Clinical practice. Microscopic hematuria". N. Engl. J. Med. 348 (23): 2330–8. doi:10.1056/NEJMcp012694. PMID 12788998. 2012 AUA Guidelines [1]
Controversy over use
There remains controversy over the use of RAD as an unofficial diagnosis. With its use not only being limited to clinical lexicon, but also transitioning to clinical literature now, more physicians are now increasingly disapproving its use in the healthcare setting.One of the largest problems with the using RAD as a diagnostic label lies in the ambiguity of its meaning, as RAD has no true clinical definition. It is either not listed or redirects to "asthma" in all major medical journal or website. In addition to that, it is also not recognized in the American Academy of Pediatrics; the American Thoracic Society; or the National Heart Lung and Blood Institute. In addition, treatments for asthma, chronic bronchitis, emphysema, or pneumonia may not be prescribed under a label of reactive airway disease. In contrast, some physicians also fear overtreatment for RAD, as patients can be prescribed inhaled beta-agonists or inhaled corticosteroids, which are medications used for asthma. If an individual with RAD doesnt have asthma, there is no evidence these treatments are beneficial. As a result of its ambiguous place in the medical field, the symptoms used to characterize it are often inconsistent and can lead to confusion in a healthcare setting.