A medical expert would be needed to confirm exactly where an "upper respiratory infection" reaches, but my guess is that choking is one of the side effects. If so, then Ana Ivanovic has been carrying the condition for more than a year.
Ivanovic cited the illness for her decision to pull out of the rest of the season, claiming it has depleted her of the physical reserves needed to cope with life on tour.
However, what has been blatantly and painfully obvious to the tennis world ever since Ivanovic's 2008 French Open win, is that her problems are not physical, but mental.
The choice to call it quits until next year is a blessed respite from forcing us to witness a talented player tie herself into mental knots each week and lose to players with considerably less talent.
Ivanovic's demise has been ugly, a prime example of failing to cope with the spotlight and pressure of being No. 1.
That is no longer an issue and may not be ever again. Ivanovic's performances have tumbled her to 12th in the rankings and she will fall further thanks to inactivity.
Even so, taking time away is almost certainly the right thing to do. So, too, will it be for Dinara Safina, the stricken world No. 1 who is about to lose her title to Serena Williams and is struggling to get a serve in play, let alone beat anybody.
The WTA Tour is concerned about burnout for its younger players and puts participation restrictions in place to combat it.
A more appropriate gesture might be to make sure the top ranking comes with a health warning - ascend to this position at your peril.
One of the sports world's most glamorous marriages crashed and burned last week, as former tennis star Chris Evert and golf legend Greg Norman split just 15 months after getting married.
Unsurprisingly, Laura Andrassy, Norman's jilted wife of 25 years, was in no mood to be charitable to the parted celebrity couple. "Being with Chris is what Greg wanted," Andrassy said to the Palm Beach Post. "Well, he got it." Ouch.
Maria Sharapova looks headed back to the top 10 after an impressive title win in Tokyo last week, her first since returning from a long injury layoff. This was a long way removed from the out-of-sorts Sharapova that floundered against Melanie Oudin at the U.S. Open and the Russian looks ready to challenge for majors once more.
Use your frequent flyer miles
Beijing is the place to be this week, as tennis returns to the scene of last year's spectacular Olympic Games.
Both the men's and women's tours will be in action - with the ladies event one of the four premier mandatory tournaments that were introduced this year. Rafael Nadal heads the men's draw and will be seeking victory once again - although there is no gold-medal prize this time around.
Last week's winners
Proton Malaysian Open, Kuala Lumpur: Nikolay Davydenko
PTT Thailand Open, Bangkok: Gilles Simon
Toray Pan Pacific Open, Tokyo: Maria Sharapova
This week's predictions
Rakuten Japan Open, Tokyo: Juan Martin del Potro