Symptoms occur in episodes - what could this be?

[worldssnk]

My father has been experiencing the following symptoms (in episodes) since late May (around 3 months). These symptoms pass after 1-2 minutes in each episode. He experiences a couple of episodes per week. Otherwise, he is fine, besides feeling weaker these days.

-Nose smells something faint - chemical-like/plastic; slight nausea
-Feels very weak & lightheaded (feels weak even after naps)
-Feels uncomfortable overall - pain not concentrated in certain area
-Cold sweat/feels cold
-Loses concentration, but has clear vision
-Heart rate nearly doubles & blood pressure is slightly higher
-Shorter breathing
-Occasionally feels hunger pangs
-Episodes will come after exerting more physical effort
-Experiencing difficult with more recent memories

He is 60 years old and Asian. Can anyone point us to a particular specialist?

We have gone to see a hematologist and cardiologist so far - nothing abnormal. His heart, liver, and kidney functions seem normal. Scheduled an appointment with a gastroenterologist. No past history of major illnesses.

[flipper336]

With some of the symptoms you listed:

-Experiencing difficult with more recent memories
-Feels very weak & lightheaded
-Loses concentration, but has clear vision
-Nose smells something faint

I would make an appointment to talk with a neurologist.

[Caryopteris]

Thyroid?  Adrenal problem?