HOPKINTON, N.H. -- Republican presidential hopeful Rudy Giuliani said Saturday he's glad to be back campaigning in New Hampshire after canceling some events because of illness.

The former New York mayor downplayed his illness to reporters after holding a town hall-style meeting with voters. He said he did not have the flu but had a very bad headache, possibly caused by overwork and lack of sleep.

"I am in good health, this is just something that came about because I was tired, not sleeping, who knows exactly why, but I had a very bad headache," he said. "They were concerned it might be other things, they ruled out just about every other possibility. It was just a bad headache."

When Giuliani boarded an airplane Wednesday and the cabin was pressurized, the headache got worse and he decided to ask the pilot to land six or eight minutes into the flight, he said. He spent the night at Barnes-Jewish Hospital in St. Louis and was released Thursday.

Giuliani, who had prostate cancer seven years ago, said a follow-up test three weeks ago found no reoccurrence of cancer.

The candidate spoke briefly and took questions in Hopkinton's snow-covered town hall.

Asked how the United States can compete in a global economy, Giuliani said Americans should pay more attention to what they are selling abroad, and less attention to whether they are buying foreign goods.

Baring product security and safety issues, he said: "If what we buy is cheaper, less expensive, then it's good for inflation. We should be more concerned about what we sell overseas. This is a great opportunity for us, we shouldn't look at the global economy and be afraid of it."

He said Americans should look at the millions of people emerging from poverty in India and China as potential customers, not as threats to jobs.

At a later event at the home of Manchester Mayor Frank Guinta, Giuliani charged that Democratic presidential hopefuls would raise taxes to extraordinary levels.

"We are going to see our tax rates going up to 39, 40, 41, 42, 43, 44, 45 percent, 46 percent," he said. "Pretty soon when you add in other taxes we are going to go back to where we used to be, over 50 percent of your money going to the government. That makes the government the senior partner in your earnings. You should be the senior partner in your earnings."