Martin Luther was known to suffer from a health problem that caused him to have to spend long periods of time alone in contemplation. These contemplations proved the inspiration for some of his greatest writings. What was the health problem from which Martin Luther suffered?

Take your pick.
"Luther had been suffering from ill health for years, including Ménière's disease, vertigo, fainting, tinnitus, and a cataract in one eye.[210] From 1531 to 1546, his health deteriorated further. The years of struggle with Rome, the antagonisms with and among his fellow reformers, and the scandal which ensued from the bigamy of the Philip of Hesse incident, in which Luther had played a leading role, all may have contributed. In 1536, he began to suffer from kidney and bladder stones, and arthritis, and an ear infection ruptured an ear drum. In December 1544, he began to feel the effects of angina."

https://en.wikipedia.org/wiki/Martin_Luther

The Meniere's Disease was the major ongoing health issue he faced, but I am not sure why it would force him to spend long periods of time alone - dizziness and tinnitus might preclude a lot of activity, but do not require isolation to treat.

Archaeologists in Germany say they may have found a lavatory where Martin Luther launched the Reformation of the Christian church in the 16th Century.
The stone room is in a newly-unearthed annex to Luther's house in Wittenberg.

Luther is quoted as saying he was "in cloaca", or in the sewer, when he was inspired to argue that salvation is granted because of faith, not deeds.

The scholar suffered from constipation and spent many hours in contemplation on the toilet seat.

The lavatory was built in the period 1516-17, according to Dr Martin Treu, a theologian and Luther expert based in Wittenberg.

"What we have found here is something very rare," he told BBC News Online, describing how most buildings preserved from that era tend to have served a grander function.
The toilet is in a niche set inside a room measuring nine by nine metres, which was discovered during the excavation of a garden in the grounds of Luther's house.

Dr Treu said there can be little doubt the toilet was used by Luther, the radical theologian who argued for a more "earthy Christianity", which regarded the entire human body - and not just the soul - as God's creation.

The Reformation, which resulted in Europe's Protestant churches, is usually reckoned to have begun when Luther nailed 95 theses to the door of Wittenberg's Castle Church on 31 October 1517.

http://news.bbc.co.uk/2/hi/europe/3944549.stm