What Causes Bleeding In Throat And Nose?

I m a 50 y.o. female. Ht-wt proportionate. Very fit life in general (27 yrs fitness trainer; active now although not up to my past levels of peak fitness). No history of bloody noses until this past year. Spontaneous, don t last long. But seem to have occurred in a cluster the past 10-14 days. May 9 & 10 I had bloody mucus in my throat in the morning. Last week had a bloody nose. Last night, middle of night, bloody nose (woke up to blood all over my sheets). Blew nose upon waking, which started a bloody nose. Later today ~1pm, blew nose again and gave me a bloody nose. What could explain this?