<prompt> Human: I was on a working holiday to San Francisco from Ireland last summer.My American health insurance Mapfre had been organised through a travel agency called USIT. When USIT asked me questions about if I had a pre-existing medical condition I answered yes. When they asked have I been admitted to hospital in the last two years I answered yes. When they asked was I on medication I answered yes. All truthful answers. However I was not aware that I was supposed to call the health insurance company Mapfre afterwards to go through it in more detail.Whilst in America I began to feel very unwell; fatigue, nausea, weakness, aches and pains. I emailed my medical consultant in Ireland and he advised me to go to the hospital. I went into St Francis Memorial hospital in San Francisco. I was in the ER for a couple of hours maybe 6. They did some tests. They didnt know what the problem was so I was released.My health insurance company Mapfre have rejected my claim stating that I did not declare my pre-existing medical condition to them so they would not be covering my hospital bills. This is a disaster for me, it was an honest oversight, I didnt know I had to contact them after informing USIT.I have received a bill from the physician that treated me in the hospital for 651 USD. I have received a bill from the hospital for 5,503.13 USD.I was only in the emergency room for a few hours, I cant understand how the bills could be this big.I am 23 years old, I have only recently finished studying at university. I have very little money and am unemployed. What should I do in this situation?  <response>: this makes me sad that there is this big of a difference in health care. as an american, if i get fatigue, nausea, weakness, aches and pains i just pop a dayquil and go to work. i wouldnt even think of going to the hospital. 