Why my platelet count is 485?

Need more info: All laboratory results need to be interpreted in the clinical context and the doctor who ordered the tests is usually in the best position to do that. Having said that, high platelet count is a often an indication of iron deficiency. It would be prudent to discuss it with the doctor who ordered the test. For good health - Have a diet rich in fresh vegetables, fruits, whole grains, milk and milk products, nuts, beans, legumes, lentils and small amounts of lean meats. Avoid saturated fats. Drink enough water daily, so that your urine is mostly colorless. Exercise at least 150 minutes/week and increase the intensity of exercise gradually. Do not use tobacco, alcohol, weed or street drugs in any form. Practice safe sex.

REPEAT TEST: This is only slightly elevated and should not be taken seriously unless a repeat test is at least that high. It may be caused by exercise. It may also be elevated after injury, bleeding, burns, infections, kidney disease, heart attack, hemolytic anemia, or loss of the spleen. It will go up after using epinephrine, heparin, isotretinoin. You could go on. So consult your Dr.