Heather Watson is confident that the illness which contributed to her first-round Australian Open exit was not another bout of glandular fever.

The 22-year-old Briton felt unwell and had to call for a medic during a 6-4 6-0 defeat to Tsvetana Pironkova in which she lost the last seven games.

Watson suffered a similar fate in Melbourne two years ago and ended up missing much of 2013 and slipping to 162 in the world rankings.

While she admits that the symptoms are a recurring problem that needs resolving, Watson does not think that this case will cause her long-term problems.

"I felt very light-headed and low on energy - it's a shame that it's today," she told BBC Sport. "I get it sometimes. I'm going to go and see the doctor afterwards and see if there's anything I can do to help with times like these in the future. I think it's just one of these things that I have, girl things. It just happens.

"It was actually the same doctor that came on court when I called the trainer for no energy two years ago. When he came on in 2013 it was the same thing. I couldn't really do much, not knowing at the time what it was.

"He said, 'We'll just do the same, give you some gels and you've just got to fight through it'. That's what I tried to do. I tried to play more aggressive so we wouldn't have too many long rallies, but I wasn't consistent enough."

Victory at the Hobart International last week took Watson to a career-high 38 in the world rankings.