My achilles' tendon hurts like a nife in the back of my tendon when i try to run walk or stand. what should i do? i run around 6 miles a day.

Stop running!: You have injured your achilles, and it is crying for rest and rehab.You will only make matters worse by not resting it. I suggest an immediate orthopedics /sports medicine consultation. Have you recently been treated with a fluoroquinolone like Cipro (ciprofloxacin)? That class of antibiotics has an adverse effect of tendon rupture. I hate the stuff

Achilles heel: it might be tendinosis ( partial tearing) or just a tight tendon. If it's not swollen it might just be tightness that needs PT. if there are any gross structural changes ie swelling I would rec an MRI. If there are structural changes you might need immobilization.