Question: Hi there,

I was hoping you could help me with a question. I am female, aged 31

After unrinating when out last night, I noticed a small piece of what looked like red thread (from clothing) in the clear urine. It was folded in half. It was not dissolving or transparent as I would have expected mucous or blood to be. I was wearing a wool skirt which from time to time collects threads from other clothes. Examining the skirt later I found both a short red and pink thread stuck to it, as well as other colours.

I looked online and became anxious, reading that this could be a sign of blood in urine. Could blood in urine look like a red string (which doesn't move/ dissolve, is about 1 inch long, bent in half)

I also recently switched my birth control pill, on Wednesday (the thread happened Friday) from Microlite to Ovranette. My period would usually be due Saturday, so I suppose if there was blood this could be a 'breakthrough' bleed from switching from one pill to another.

I am not sure what to do next. I feel silly in one way as I really believe it may just have been from clothing, as it was a single fibre. I feel maybe I should wait and see if there is any further sign of red fibre or mucous to know if it is in fact bleeding.

If this was a sign of something serious, would there be more than just one fibre, and would I see at least traces of actual liquid blood? My grandfather had kidney cancer so I am anxious about any kidney symptom.

Your help is much appreciated

i have had no pain associated with this, and also have urinated five times since with no threads or any discoloration visible.

Thank you Doctor for your reply.

I would not describe the red as a streak, it was more string like, in a 'U' shape. Would that make it less likely that it was blood? Does blood in urine usually colour the urine itself or appear as drops?

I would like to know what to look for.

Thank you for your advice.