PUNCTUATION AND CAPITALIZATION

The patient has had recurring episodes of paroxysmal nocturnal dyspnea and 3 pillow orthopnea. Associated symptoms such as lightheadedness, breathlessness, and exertional dyspnea occur during daytime hours.

Is this statement correct for spelling, punctuation and capitization?
Should 3 pillow have a hyphen?

I would say so, yes.

... 3-pillow orthopnea.

Everything else looks fine.

In terms of spelling, punctuation, and capitalization, there are a few corrections that need to be made:

"The patient has had recurring episodes of paroxysmal nocturnal dyspnea and 3-pillow orthopnea. Associated symptoms, such as lightheadedness, breathlessness, and exertional dyspnea, occur during daytime hours."

Regarding the specific question about whether "3 pillow" should have a hyphen, it depends on how it is being used. If "3 pillow" is functioning as a compound modifier before a noun (e.g., "3-pillow orthopnea"), then it should have a hyphen. However, if "3 pillow" is not modifying a noun and is simply describing the severity or extent of the condition, a hyphen is not necessary (e.g., "The patient experiences orthopnea with 3 pillows.").

In this case, it seems like "3 pillow" is being used as a compound modifier to describe the severity of orthopnea, so a hyphen is necessary.

Remember that correct punctuation, such as using commas to separate items in a list, and proper capitalization, like capitalizing the first letter of each sentence and proper nouns, are important for clarity and readability.