Do you mean blood clots in urine or thrombi in the blood vessels?
Blood clots are caused by certain surgical procedures and diseases.
It could be blood clots.
People get blood clots for different reasons. The most common reason why people get blood clots is because there blood is to thick and cannot function right.
Blood clots in a period are due to blood that was stationary long enough to begin to congeal.
No, infection. The black blood clots are just old blood that didn't shed the month before.
No. Blood clots in urine signify something more serious than a mere infection. See your doctor about it, and s/he'll figure out what exactly is going on.
The most usual cause of blood in the urine is a kidney stone.
* you see blood clots which are actually clots of tissue in your menstruation -- don't worry, this is a normal occurrence and is no cause for alarm. Blood clots such as these are perfectly normal because menstruation involves the shedding of the lining of the uterus.
Hemophilia is one disease in which blood clots poorly.
causes your blood not to stick together ans form clots.
Sperm naturally clots even if not mixed with urine. The sperm clots in order to help make a "plug" so it doesn't come out of the vagina before some of the other sperm can have a chance to fertilize the egg.