<s>[INST] hi .... i am 25 yrs old and in the past few months have noticed what seems to be blood in my semen when i ejaculate ... at first it was brownish and it went away for a few months .... last night i had sex after 2months of previous ejaculation and noticed it reddish and darker .... i wonder why this could happen .... does placing laptop on ur crotch area cause this ? [/INST] Hi, I suggest that you get the semen analyzed. This way, we can tell what the exact composition of the semen is and what the blood in it is all about. Blood in semen could be caused by excessive sexual activity or masturbation, an infection, a prostate disease, etc. However, I will want to think that excessive sexual activity is probably the cause. This will be confirmed by the absence of no other findings suggestive of an infection. In all, probably linked to excessive sexual activity. Semen analysis would help with this. Hope I have answered your query. Let me know if I can assist you further. Wishing you all the best.  </s>