The BBC reports the suspended Fifa president suffered what has been described as “a small breakdown” and “nervous shock”, but is expected to make a full recovery.
A spokesman said Mr Blatter told him: “My brain and heart are fine, but my body is letting me down.”
Mr Blatter, 79, was provisionally suspended for 90 days last month amid a corruption scandal.
The criminal case centres on whether he misused Fifa money by making a 2m euro (£1.35m) payment to Uefa president Michel Platini for consultation work. They both deny any wrongdoing.