Many causes. There are many causes to blood in urine. My usual workup includes kidney ultrasound, urinalysis, analysis of urine for protein. If all of these are nonrevealing, cystoscopy can be performed also. I do recommend that you see your physcician for further evaluation.
Infection, tumor, etc. Most common cause is a bladder infection, usually associated with symtoms of urinary frequency, buring on urination, foul smelling urine &? Pain. Can be a sign of cancerin urinary tract anywhere from kidney -> bladder, prostate or urethra, kidney disease such as glomerulonephritis, kidney stone, blood vessel abnormality, or medications. Microscopic blood from all of above + interstuitial cystitis.
No. Blood in urine is acute urinary tract infection, tuberculosis or malignancy until proven otherwise. There are other less frequent causes, but Azithromycin is not likely one of them.
Does IgA nephropathy always cause blood in urine when you are having colds? Is hematuria always present in urinalysis?
It well may. Iga nephropathy ranges from trivial to serious. I'm glad you had the diagnosis made successfully. It may flare whenever there is a musocal infection, since IgA is the antibody that's most typically found there.