What kind of cancer can it be if you have blood in the urine?

Not necessarily CA: Blood in the urine (hematuria) has many possible causes, including kidney/bladder stones or kidney cysts, urinary tract infections, urethral trauma. Cancers commonly associated with hematuria include renal cell carcinoma (a kidney cancer), and bladder cancer. (see also dr. Klauber's very important comment.).

Needs evaluation: Any degree of blood in the urine (whether its microscopic or visible/gross) needs to be fully evaluated. Sources of blood in the urine may be either benign (e.g., infection, stones) or malignant. A malignancy anywhere in the urinary tract may cause hematuria - from the kidenys all the way dwn to the urethra. This is why patients need imaging and cystoscopy to evaluate hematuria.