I have a burning pressure in my chest. spirometry values were normal. what could be the cause of this?

Possibilities: Most of the time burning sensation in the chest is related to heart burn or acid reflux. It is true that some patients with asthma may have a tightness/burning in the chest but it is not as likely as acid reflux. I would consider a trial of an antacid and doing some easy interventions such as not eating before bed, decreasing acidic/citrus food intake and not smoking.

Depends: Could be gastro-esophageal reflux disease (gerd), or acid reflux. Could be angina. Could be neuropathy from a pinched nerve coming out of the thoracic spine. Could be shingles.