The former Wimbledon champion revealed he battled a low-grade illness during his run to the Roland Garros semi-finals.
Murray also confirmed coach Amelie Mauresmo will not join his back-room staff for next week's Aegon Championships, but will be on hand for Wimbledon.
The 28-year-old will start his quest for a fourth title at Queen's Club on Monday, but will face a qualifier so must wait until the end of Sunday's play to discover his first-round opponent.
"They were three full days off any training or anything. I needed to rest and recover. I was actually sick for about a week, really, so I needed to recover from that too.
Andy Murray and Kim Sears tie the knot at Dunblane Cathedral in pictures:
"To be honest, I actually felt okay, but the day I played (David) Ferrer (in the quarter-finals) I didn't feel great.
"When I got on the court and started running around it was fine, but when I got back my left eye closed up, and I had a bad cough for a couple of days.
"I don't know whether I was just run down or tired, but it had been a long few weeks - but I feel fine now."
Tennis bosses have this year added an extra week's break to the global calendar between the end of the French Open and the start of Wimbledon.
Queen's has become an ATP 500 event, worth double the rankings points and with the winner's prize money jumping from around 80,000 euros last year to in excess of 380,000 euros this summer.