I'm a 51 year old woman, fit & healthy, but been feeling weary lately & waking up feeling headachy,,stuffy & groggy. this usually clears by lunchtime,?

Allergies: Sounds like you have developed an allergy problem. Since it seems to happen mostly at night I would start by replacing your pillows and bedding with hypo-allergenic products. If you have any new pets that sleep with you, I would have them sleep in another room. You could also get an air purifier for the room. Taking Benedryl at bedtime may also be helpful.

Allergies?: There could be many causes for your symptoms. Because you said you were stuffy it is possible that you are having allergy symptoms. Try taking a non-sedating antihistamine such as loratadine once a day to see if this helps. Also make sure you are drinking plenty of water and add a multivitamin. It would be good to see your doctor for a check up and blood tests just to rule out other causes.