Students are being advised to look after their health in the run up to the State exams.
115,000 pupils will sit the Junior and Leaving Certificates from Wednesday.
The Irish Pharmacy Union says that the stress of studying can make students forget to look after their health, particularly if they've an ongoing condition such as asthma or eczema.
Pharmacist Caitriona O'Riordan has this advice: "We do have people getting headaches around this time of year from stress, from tiredness, from dehydration really.
"They just have the heads down and they don't have time to think, so we suggest you study in a well ventilated room and to be sure to take plenty of regular breaks.
"Eat good food, I know it's tempting to treat yourself with junk and sweets at this time but really you're going to feel better if you eat correctly, and drink plenty of water," she said.