The most common and most likely answer to this crossword clue is the 4 letter word GOUT
I've seen this crossword clue in Independent
G
O
U
T
More clues leading to the result GOUT
- Complaint received about university
- Painful disease it’s good to have dismissed
- Complaint of German leader? Impossible!
- Illness when circular object is stuck in alimentary canal
- Disease causing swelling of beer belly containing penultimate part of gallon
- Realised, as we did, Brexit not to Macron’s taste?
- An extremely painful condition
Buddy explains!

The straight part
We know that "Painful disease" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case painful disease = gout.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 GOUT mean?
GOUT noun- An extremely painful inflammation of joints, especially of the big toe, caused by a metabolic defect resulting in the accumulation of uric acid in the blood and the deposition of urates around the joints.
- (usually followed by of) A spurt or splotch.
- A disease of wheat and cornstalks, caused by insect larvae.
- To spurt.
- Taste; relish