1. Hematuria With Negative Urine Culture
2. Occasional Gross Hematuria
3. Occasional Microscopic Hematuria

.The visible sign of hematuria is pink, red or cola-colored urine — the result of the presence of red blood cells. It takes very little blood to produce red urine, and the bleeding usually isn't painful. If you're also passing blood clots in your urine, that can be painful. Hematuria or presence of blood in the urine can be painless or painful. Painless hematuria may be caused due to underlying medical problems like stone disease, urinary tract infections (UTI), glomerular disease, kidney infections, bladder disease, chronic kidney disease, and tumors.

Mark A Perazella, MD, FACP

• Professor of Medicine
• Yale University School of Medicine

• Hematuria is the presence of red blood cells in the urine. If there are enough red cells, the urine can become bright red, pink or cola colored. Often, however, the urine appears completely normal because there is not enough blood to cause a color change. In this case, the condition is called 'microscopic' hematuria.
• The causes of hematuria vary depending on the age of a woman and the underlying risk factors. Common Causes of Hematuria or Bloody Urine in Women are: Cystitis, Urinary tract infection (UTI), kidney infection, and pyelonephritis; Kidney stones and Ureteral stones can usually cause microscopic hematuria, but occasionally gross hematuria occurs.

Richard J Glassock, MD, MACP

• Editor-in-Chief — Nephrology
• Section Editor — Glomerular Diseases
• Emeritus Professor
• The David Geffen School of Medicine at UCLA

Michael P O'Leary, MD, MPH

• Section Editor — Urology
• Professor of Surgery, Harvard Medical School
• Senior Urologic Surgeon, Brigham and Women's Hospital

Albert Q Lam, MD

• Deputy Editor — Nephrology
• Lecturer on Medicine
• Harvard Medical School

INTRODUCTION

Hematuria that is not explained by an obvious underlying condition (eg, cystitis, ureteral stone) is fairly common. In many such patients, particularly young adult patients, the hematuria is transient and of no consequence [1]. On the other hand, there is an appreciable risk of malignancy in older patients (eg, over age 35 years) with hematuria, even if transient [2-4]. However, even among older patients, a urologic cause for the hematuria can often not be identified (61 percent in a series of 1930 patients referred to a hematuria clinic) [2]. (See 'Transient or persistent hematuria' below.) (Related Pathway(s): .)

The etiology and evaluation of hematuria in adults will be reviewed here (figure 1 and algorithm 1). The approach in children is discussed separately. (See 'Evaluation of microscopic hematuria in children' and 'Evaluation of gross hematuria in children'.)

DEFINITION OF HEMATURIA

Hematuria may be visible to the naked eye (called gross hematuria) or detectable only on examination of the urine sediment by microscopy (called microscopic hematuria).

Hematuria With Negative Urine Culture

Gross hematuria — Gross hematuria is suspected because of the presence of red or brown urine. The color change does not necessarily reflect the degree of blood loss, since as little as 1 mL of blood per liter of urine can induce a visible color change. In addition, the intermittent excretion of red to brown urine can be seen in a variety of clinical conditions other than bleeding into the urinary tract (see 'Urinalysis in the diagnosis of kidney disease', section on 'Red to brown urine'). Gross hematuria with passage of clots usually indicates a lower urinary tract source but can be seen with some forms of intrarenal bleeding (eg, kidney cancer).

As contamination with blood is a possibility in menstruating and postpartum women, urine for analysis is best obtained when the other cause of bleeding has ceased. If this is not possible, a tampon can be inserted, and urinalysis can be obtained after the perineum is cleansed.

Occasional Gross Hematuria

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Occasional Microscopic Hematuria

1. Diagnosis, evaluation, and follow-up of asymptomatic microhematuria (AMH) in adults: American Urological Association (AUA) Guideline http://www.auanet.org/content/media/asymptomatic_microhematuria_guideline.pdf (Accessed on December 11, 2012).
2. Fogazzi GB, Ponticelli C, Ritz E. The Urinary Sediment: An Integrated View, 2nd ed, Oxford University Press, Oxford 1999. p.30.
3. Hebert L. Glomerular diseases: The American College of Physicians Nephrology Medical Knowledge Self Assessment Program (MKSAP), American College of Physicians-American Society of Internal Medicine, Philadelphia 1998.
4. http://jamanetwork.com/journals/jamainternalmedicine/fullarticle/2618818 (Accessed on April 18, 2017).