Red blood cells (or any type of cells) in the urine should be investigated. The most common reason is a urinary tract infection- this may or may not be painful, but usually you have burning.
In hematuria, your kidneys - or other parts of your urinary tract - allow blood cells to leak into urine. A number of problems can cause this leakage, including:
- Urinary tract infections. Urinary tract infections are particularly common in women, though men also get them. They may occur when bacteria enter your body through the urethra and begin to multiply in your bladder. The infections sometimes, though not always, develop after sexual activity. Symptoms can include a persistent urge to urinate, pain and burning with urination, and extremely strong-smelling urine. For some people, especially older adults, the only sign of illness may be microscopic blood.
- Kidney infections. Kidney infections (pyelonephritis) can occur when bacteria enter your kidneys from your bloodstream or move up from your ureters to your kidney(s). Signs and symptoms are often similar to bladder infections, though kidney infections are more likely to cause fever and flank pain.
- A bladder or kidney stone. The minerals in concentrated urine sometimes precipitate out, forming crystals on the walls of your kidneys or bladder. Over time, the crystals can become small, hard stones. The stones are generally painless, and you probably won't know you have them unless they cause a blockage or are being passed. Then, there's usually no mistaking the symptoms - kidney stones, especially, can cause excruciating pain. Bladder or kidney stones can also cause both gross and microscopic bleeding.
- Enlarged prostate. The prostate gland - located just below the bladder and surrounding the top part of the urethra - often begins growing as men approach middle age. When the gland enlarges, it compresses the urethra, partially blocking urine flow. Signs and symptoms of an enlarged prostate (benign prostatic hyperplasia, or BPH) include difficulty urinating, an urgent or persistent need to urinate, and either gross or microscopic bleeding. Infection of the prostate (prostatitis) can cause the same signs and symptoms.
- Kidney disease. Microscopic urinary bleeding is a common symptom of glomerulonephritis, which causes inflammation of the kidneys' filtering system. Glomerulonephritis may be part of a systemic disease, such as diabetes, or it can occur on its own. It can be triggered by viral or strep infections, blood vessel diseases (vasculitis), and immune problems such as IgA nephropathy, which affects the small capillaries that filter blood in the kidneys (glomeruli).
- Cancer. Visible urinary bleeding may be a sign of advanced kidney, bladder or prostate cancer. Unfortunately, you may not have signs or symptoms in the early stages, when these cancers are more treatable.
- Inherited disorders. Sickle cell anemia - a chronic shortage of red blood cells - can be the cause of blood in urine, both gross and microscopic hematuria. So can Alport syndrome, which affects the filtering membranes in the glomeruli of the kidneys.
- Kidney injury. A blow or other injury to your kidneys from an accident or contact sports can cause blood in your urine that you can see.
- Medications. Common drugs that can cause visible urinary blood include aspirin, penicillin, the blood thinner heparin and the anti-cancer drug cyclophosphamide (Cytoxan).
- Strenuous exercise. It's not quite clear why exercise causes gross hematuria. It may be trauma to the bladder, dehydration or the breakdown of red blood cells that occurs with sustained aerobic exercise. Runners are most often affected, although almost any athlete can develop visible urinary bleeding after an intense workout.
As you can see, there are a number of causes, some of which are more concerning than others.It is really difficult to say where the blood is coming from just based on the timing, but in general, if it is in the urethra, then you would see blood in the beginning. If it is in the kidneys, the entire urine should have some blood. And if it is in the bladder (like from stones or inflammation or tumor), you would have bleeding at the end of your urination (like you are). So I suspect it is in your bladder...
This may have been just a transient event and you will not need a workup.
I would recommend that you make an appointment to be seen by your doctor asap. You may need a referral to a urologist They are going to recheck your urine again to make sure that it is clear. If you still have the red blood cells, then they usually start off with a cystoscopy to check your bladder. In some cases they may do a CT or MRI of your abdomen to look at the kidneys for any tumors or abnormalities.
Hang in there.
If you have any fever, back pain, vomiting or other concerning symptoms, do not wait for you appointment, go to the ER