About 15-20 hairs on pillow in morning. Male, 36. Cause for concern? Or normal?

It is not unusual to lose 10-20 hairs per day,in fact you can normally lose 50-100.I would recommend a thorough  history and physical exam by a Dermatologist or experienced Hair Restoration surgeon to determine your cause of hair loss and recommend methods to prevent further loss.

Unless this started happening very suddenly or you can see/feel significant differences in the density of your hair still on your scalp, this doesn't seem too concerning. People can lose over 100 daily just as part of their natural hair growth cycles, depending on the density of their hair.

That is a rather high number to be seeing on one's pillow for a person who shampoos every day or two. If you always see 15, then that's a different story of course.Well it's true one can lose 50 or more hairs daily these come out with force. Spontaneous loss of 15-20 hairs on one's pillow is not typical for individuals who shampoo frequently.If you feel you are experiencing hair loss - see a dermatologist for guidance.