This may be due to aesthetic or social-standing reasons, in areas where a lighter skin tone is considered to be a sign of wealth or beauty. Also, skin-lightening creams containing compounds such as hydroquinone are commonly used to help with hyperpigmentation disorders such as melasma.Hydroquinone is the compound most frequently used in skin-whitening products. Due to concerns about its side effects, it was almost banned by the FDA in 2006, as  medical issues of carcinogenicity and reports of disfiguring ochronosis existed. In the European Union hydroquinone has been banned in cosmetic creams since 2000.Long-term use of creams containing this compound may lead to exogenous ochronotic lesions. The duration of use is directly proportional to the risk of developing the condition, with most cases occurring after years of use. Around 10–15 million skin lightening products are sold annually, with Japan being the major buyer. Pathophysiology
Ochronosis occurs because of deposition of phenols (such as homogentisic acid and hydroquinone) as plaques in the matrix of cartilage. The pigments can also be incorporated into collagen and elastin fibers. In the skin, the pigment alters the structure of the fibers, causing enlargement and curling. The embedded pigments also form crosslinks with pigment depositions in adjacent fibers, stabilizing and reducing the elastic recoil of the fibers. This results in hardening of elastic structures, increasing their rigidity and brittleness. Once ruptured, the exposed pigments cause a foreign body reaction and inflammation. This pigment deposition also invokes deposition of hydroxyapatite, the mineral responsible for bone calcification, further hardening the connective tissue.
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]