Weight gain,but possibly combination,or not at all,theres many reasons why your knee could be hurting you.Go to the Doctor,he can start treatment right away and give you a Diagnosis.for now just relax try to keep off the knee and while walking be cautious not to step wrong or off or apply to much pressure this could cause pain to worsen and or injury.Pray and get to theDoctor.elevate you leg only quarter.
Definitely!!
Have you tried Extracorporeal Shock Wave Therapy (ESWT) ? google it! it's for plantar fasciitis