The most common and most likely answer to this crossword clue is the 7 letter word HYPOXIA
H
Y
P
O
X
I
A
Buddy explains!
The straight part
We know that "result of getting too high (in altitude!)" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case result of getting too high (in altitude!) = hypoxia.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does HYPOXIA mean?
HYPOXIA noun- A condition in which tissues (especially the blood) are deprived of an adequate supply of oxygen; anoxia
- A reduced concentration of dissolved oxygen in an aquatic environment.