But, in fact, most STDs do not present symptoms, she said.

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Dr Hudson said this was not a criticism of doctors because eating disorders tended to present with vague symptoms, but highlighted a gap in training.

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But the government's Chief Medical Officer, Professor Liam Donaldson, has claimed that, because of the huge number of people don't bother to present with their symptoms, the number is far higher.

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"To be prudent, I'd recommend cutting exercise duration and intensity when symptoms are present, " says Woods.

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In the DSM5 criteria it is identified that symptoms are present in early childhood but may not fully manifest for a diagnosis until social demands exceed social capacity.

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At present, approximately eight million people develop symptoms each year, and two million die.

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At present the monitoring stops after five years if the patient has no adverse symptoms.

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Having access to this data is critical, particularly when patients present with conditions with which physicians may be unfamiliar, such as the symptoms of radiation exposure.

FORBES: Written By Arvind Subramanian

For patients who already have some symptoms of cognitive decline, a positive scan suggests that moderate to frequent amyloid plaques are present in the brain, which is consistent with Alzheimer's disease.

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