You have a cold, but instead of getting better, it keeps getting worse, so you've been sent to desk duty.

You've been coughing badly for weeks and have other, actually, common cold symptoms. You think it just hit you hard. After all, you're never sick. However, at some point you cough up blood but don't tell anyone.

During a briefing, you have a coughing fit and cover your mouth with a tissue. Ghost is shocked as he sees the bloody tissue and takes you to the side after the briefing