It is highly likely that your wife has a bladder infection called Cystitis that is causing the blood to be seen in the urine.
As a home remedy, you wife needs to drink plenty of water.
If she experiences any pain or discomfort when urinating or discomfort in her lower belly, she can have a glassful of water with a teaspoonful of Bicarbonate of Soda. She can have a solution of this 1 every hour for 3 hours. No more. The Bicarbonate of Soda will neutralise the acidity in the urine that makes it feel so uncomfortable.
Make an appointment to see the doctor who will check the urine and prescribe an antibiotic if this is required.
Based on my experience, blood in the urine was due to urinary tract infection. I felt pain in my vagina when passing urine and drops of blood came out after the urine. My gynecologist gave me antibiotics to treat the infection. If your wife feels the same, better take her to the doctor immediately.
I recently had a urine test. It contained microscopic blood. I am now being investigated by a urologist for bladder infection. My understanding is that ANY blood in the urine visible or microscopic should be referred to a urologist. It may be an ordinary urinary tract infection (UTI) as Mikah says or a Complicated UTI or something else.
Take any and all blood and urine results to the urologist who will most likely perform more blood and urine tests and perhaps prescribe antibiotics like NORFOLOXACIN.
The doctor won't prescribe an antibiotic if there is blood in the urine with no infection.
There are also different types of antibiotics that treat urinary infections. A urine specimen that is examined at the laboratory can detect which bacteria is causing an infection as to which antibiotic to use.
Blood in the urine in men is looked at more vigorously than that in women.
In men blood in the urine can be due to prostate problems as well as urinary tract.
It also depends on your doctor with regard to being referred to a urologist. If the blood in the urine is caused by nitrites, this would indicate a bladder infection that would be treated by an antibiotic with no need to be referred to a urologist.
Kidney stones can also cause blood in the urine as well as infections. A kidney stone can be as small as a grain of sand, but if this starts to move, this is when infections and pain occur - sometimes very severe with high temperature, vomiting and diarrhea.
It is imperative to drink plenty of fluids and especially water.