We often hear that social networks can be fine for emotional health by reconnecting us with old friends, helping us build professional contacts and countering isolation, but Italian doctors have reported a case where logging onto Facebook made an 18-year-old man hyperventilate.

The patient, whose asthma was well-controlled with steroid inhalers and Singulair pills, began having more asthma attacks when he logged onto Facebook and learned that his ex-girlfriend had un-friended him and friended "several new young men." Frustrated by being cut off from his former flame, the jilted boyfriend became her Facebook friend under a nickname and regained access to her profile picture.

However, the sight of her picture left him hyperventilating and short of breath, "which happened repeatedly" as he called up her profile, wrote Dr. Gennaro D'Amato, a respiratory and allergy specialist at the High Specialty Hospital A Cardarelli in Naples, Italy, in this week's issue of The Lancet.