If a platelet count falls from 120x10^9/l, to 94x10^9/l, to 45x10^9/l, to 24x10^9/l, to17x10^9/l, to 23 x10^9/l and then to 8x10^9/l, how serious is the situation? what should be done?

See hematologist: It is serious. You need to be admitted in the hospital and to see a hematologist. Some blood test, imaging study and a bone marrow biopsy should be done. Spontaneous bleeding can happen when your platelet is less than 10k.

Need hospitalization: You need to go asap to emergency room and be admitted it is serious at this age we need to rule out leukemia with this dramatic drop second thing a condition called myelodyspalstic syndrome which is a pre - leukemic condition the third thing is HIV hepatitis c immune destruction of the platelets which is benign condition harmless.

Very serious: You list "myeloproliferative disorder" on your list of conditions so i trust you are under the care of a hematologist. You also have other very serious health problems (chf, type ii diabetes, copd). The first thing that must be done is that the two of you have a frank and honest talk about your wishes in a situation that is deteriorating rapidly. Be strong and discerning, and best wishes.