The Israeli army chief of staff, General Dan Halutz, fell ill Friday and was taken to hospital for tests, Channel 10 television reported.
The general had complained of stomach pains and was admitted to a hospital in northern Israel for tests and was later released, the report said.
A second TV channel said he was in hospital for about an hour.
Earlier Halutz claimed "enormous" damage had been inflicted on the Shiite militants of Hezbollah since Israel launched its offensive on Lebanon on July 12, with hundreds of its fighters hit.
Hezbollah admits to having lost 30 men in Israeli attacks.
More than 420 people, mostly civilians, have been killed in Lebanon since the capture of two soldiers by Hezbollah in a deadly cross-border raid sparked the onslaught.
A total of 51 Israelis have also died in cross-border fighting, mostly soldiers, with the government deciding Thursday to call up three divisions of reservists — as many as 30,000 more troops.
The Israeli military is also engaged in another offensive in the Gaza Strip to retrieve a third serviceman captured during a June 25 raid by Palestinian militant groups on a border post.
