17, female. i noticed that, when i suck on my tongue and spit out, i find small streaks of blood in my sputum... why is this? thanks

A bit of digging: Suggests that this might be due to superficial irritation of your tongue made worse over a night perhaps from open mouth sleep. Some tongues may have slightly unusual surface sensitivity. If you are troubled, see a Dr or ENT. If not, don't draw it out by sucking hard and try some sucking lozenges to keep mouth moist/closed during sleep. Best wishes.