Being too stretched-out can cause it, but you often also feel other discomfort at the base of the neck and upper middle back. What's the height differential between the bars and saddle, raising h-bars sometimes helps. Saddle adjustment can have some bearing. Not just fore/aft but also tilt. While there's not always much room for adjustment because of *other* comfort issues, raising the nose a little sometimes helps. Having the back high almost always increases hand pressure.