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 SAN FRANCISCO — Larry Page, Google’s chief executive, said on Tuesday that he had a rare and chronic health problem that makes him hoarse and constricts his breathing. 
 
 The announcement was the first time that Mr. Page, 40, had explained his voice troubles. Nearly a year ago, Google said that he would avoid public speaking for a time because he had lost his voice. Since then, he has spoken publicly, but with a weak, raspy voice. 
 
 One of Mr. Page’s vocal cords was paralyzed after a viral infection 14 years ago, and the second was left with limited movement after a cold last summer. Voice specialists said that it was extremely rare for a patient to experience paralysis or limited movement in both vocal cords, and that, as of now, the condition could not be reversed. 
 
 “Thankfully, after some initial recovery, I’m fully able to do all I need to at home and at work, though my voice is softer than before,” Mr. Page wrote in a post on Google Plus. 
 
 “And Sergey says I’m probably a better C.E.O. because I choose my words more carefully,” he added, referring to Sergey Brin, who founded Google with Mr. Page. 
 
 The condition can become life-threatening, doctors say, when it inhibits breathing. Mr. Page addressed that in his post. 
 
 “Vocal cord nerve issues can also affect your breathing, so my ability to exercise at peak aerobic capacity is somewhat reduced,” he wrote. “That said, my friends still think I have way more stamina than them when we go kitesurfing!” 
 
 Mr. Page also said that in 2003 he learned that he had Hashimoto’s thyroiditis, an inflammatory thyroid condition that he said had caused him no problems. He said it was unclear whether that condition was related to his vocal cord paralysis. 
 
 Hashimoto’s thyroiditis is an autoimmune disorder that is the most common cause of hypothyroidism in the United States, particularly among middle-aged women, and can cause fatigue, hoarseness, pain and stiffness, according to the Mayo Clinic. It is treated with hormone replacement drugs, though doctors often delay treatment if the thyroid is functioning normally. Mr. Page did not say whether he was receiving treatment. 
 
 His health had raised concerns among Google shareholders, particularly after the death of Steven P. Jobs, Apple’s former chief executive, and questions about an executive’s responsibility to reveal health problems. Until now, Google refused to provide details about Mr. Page’s condition. 
 
 “It’s never a positive,” Colin Gillis, an analyst covering Google at BGC Partners, said on Tuesday. Still, though Mr. Gillis said he had expected Mr. Page’s announcement to hurt Google’s stock price, shares rose 1 percent. 
 
 Doctors have ruled out cancer, according to a person briefed on Mr. Page’s health. Mr. Page speaks regularly in meetings and has continued to run daily operations at Google, the person said. Though a Google spokeswoman last year said that Mr. Page had lost his voice, the person said on Tuesday that he had, in fact, never lost his voice completely. 
 
 Mr. Page also said he had given a personal grant to the Voice Health Institute, a group founded in 2003, for a research program on improving vocal cord nerve function. The research will be led by Dr. Steven M. Zeitels, a laryngeal surgeon at Massachusetts General Hospital and one of several doctors who treated Mr. Page. 
 
 He did not disclose the size of the donation, but the person briefed on Mr. Page’s health said it was more than $10 million. 
 
 “The Pages’ generosity will enable us to help steward a new era of pioneering surgical, medical and engineering innovations that will provide new solutions for the millions of individuals suffering from voice loss and breathing problems in the upper airway,” said a statement from John L. Ward, president of the Voice Health Institute. Well-known singers like Julie Andrews, Steven Tyler and Lionel Richie are on the institute’s advisory board. To begin, the group, which is based in Boston, has asked people with a similar condition to Mr. Page’s to complete a survey about their symptoms. ||||| When Google CEO Larry Page stopped talking at events last summer, some company watchers feared the worst. But Page revealed on Tuesday that he's perfectly healthy, and his raspy voice is due to vocal cord paralysis. 
 
 Page wrote in a post on his Google+ page that his doctors speculate it's virus-based nerve damage from a terrible cold he suffered 14 years ago, though they can't pinpoint a definitive cause. That 1999 cold left him with paralysis of the left vocal cord, and another cold last summer paralyzed the right cord. 
 
 "Thankfully, after some initial recovery I'm fully able to do all I need to at home and at work, though my voice is softer than before," Page wrote. "And giving long monologues is more tedious for me and probably the audience." 
 
 Page's voice issues surfaced last June, when Google (GOOG) announced he had "lost his voice" and would skip the company's upcoming quarterly earnings call and other events. Page didn't appear in public until Google's Zeitgeist conference in October, where he declined to comment on his health but sounded notably hoarse. 
 
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 Corporate governance pundits called on Page to disclose his condition given that he's the CEO of a public company, but neither he nor Google released details. Once Page did begin speaking at events like earnings conference calls, his short statements fueled more speculation. 
 
 Page didn't say why he ultimately revealed his condition, or why he chose Tuesday to do so. 
 
 Google's I/O developer conference kicks off on Wednesday, but Page hasn't attended the event in recent years. Fellow co-founder Sergey Brin usually handles the big I/O announcements. Page wrote that Brin told him "I'm probably a better CEO because I choose my words more carefully. So surprisingly, overall I am feeling very lucky." 
 
 Related: Will Google stock hit $1,000? 
 
 Page added that people tell him he has sounded better lately, and he has worked with vocal cord specialists to help him improve. 
 
 Paralysis of both vocal cords is very rare, Page said, which means researchers have little data to work with. Page also said that he is funding a "significant research program" through the Voice Health Institute, and he included a link to a survey seeking data from vocal cord paralysis sufferers.
– Google CEO and co-founder Larry Page has broken his silence about the condition that prevented him from speaking publicly last summer, sparking fears he may have had an undisclosed, life-threatening illness. Page says he is in good health, but his left vocal cord has been paralyzed since he caught a bad cold in 1999, and the second one was paralyzed by another cold last summer, CNN reports. Paralysis in both cords is extremely rare and experts say the condition—which has left Page with a weak, raspy voice—can't currently be reversed, the New York Times reports. In a post on his Google+ page, Page said he also has the thyroid condition Hashimoto's thyroiditis, and it's not clear whether it is related to his vocal cord problems. "Thankfully, after some initial recovery, I’m fully able to do all I need to at home and at work, though my voice is softer than before," he wrote, adding that Google co-founder Sergey Brin says Page is "probably a better CEO because I choose my words more carefully." Page says he is funding a Voice Health Institute research program to help people with the same condition.