Sharp Heel Pain With Your First Steps in the Morning
This is the most distinctive symptom of plantar fasciitis and the one NHS clinicians use as a primary diagnostic indicator. During sleep the plantar fascia shortens and tightens. When you place weight on the foot with your first steps, the fascia is suddenly stretched and small micro-tears occur at the heel attachment. This causes the characteristic sharp stabbing pain.
The pain is typically worst in the first 5 to 10 steps, then gradually eases as the fascia warms up and becomes more flexible.