The doctors stood at the end of my bed, looking mystified. I was terrified \u2014 I thought I was going to die. I\u2019d arrived at hospital three days before with an internal temperature of 42C; now my organs were failing. As a GP myself, I knew how serious my condition was.<\/p>\n
I was 39 with a wonderful husband, three beautiful children and a successful career but I didn\u2019t have an immune system strong enough to fight this fever.<\/p>\n
After four weeks in hospital I was eventually discharged with the unsatisfactory diagnosis of PUO \u2014 pyrexia of unknown origin \u2014 which basically means \u201cyou were very hot but we don\u2019t know why\u201d.<\/p>\n
This was a life-changing moment. Whatever the diagnosis, the cause was clear to me: burnout. For years, I\u2019d pushed my body to breaking point.<\/p>\n
Determined to see my children, then aged ten, nine and five, grow up, I decided that I needed to use my medical knowledge to reinvent myself. The biohacks (as the data analysis and habits I deployed to optimise my health are called) have proved so successful that now, aged 53, my biological age \u2014 that is, the age of my cells, ascertained with a blood test that analyses protein markers of inflammation, central to ageing \u2014 is that of a 20-year-old.<\/p>\n
Strange as it sounds, science shows we can bring our age down in a measurable way. I\u2019m proof of this. And while biohacking might bring to mind wealthy tech titans trying to live for ever, many of the techniques I now teach clients as a longevity doctor are free, take minutes and can add decades to our lives.<\/p>\n
\u2022 How I got Rod Stewart, 80, fit to perform<\/a><\/p>\n I believe we should set a goal for how long we want to live, just as we set goals for everything else, and work towards it. I tell clients that, with the right approach, there\u2019s no reason they can\u2019t make one million healthy hours, or 114 years. Unlikely as it might sound, that\u2019s my intention.<\/p>\n Certainly, I feel barely recognisable from the partner in a GP practice who was too busy to go to the loo between patients, surviving on biscuits and writing prescriptions into the night after the children had gone to bed. I thought I could manage the juggle, never slowing down enough to notice the warning signs \u2014 constantly aching neck, waking up exhausted after four hours\u2019 sleep \u2014 that I was about to crash.<\/p>\n I worked through the fever I developed one Friday morning in 2011 so as to not let colleagues down. But by the following afternoon I was too ill to eat, move or make decisions. My husband, Manish, a dentist who was then 42, rushed me to hospital near our London home where, thinking that my temperature must be caused by a severe infection, doctors put me on a potent intravenous antibiotic drip.<\/p>\n \u2022 On the paradise island where millionaires go to avoid death (and taxes)<\/a><\/p>\n When that didn\u2019t help they performed emergency abdominal surgery in the middle of the night as they suspected that an abscess in my abdomen could be to blame. It wasn\u2019t. Days later, weak from surgery and with my kidney and liver function deteriorating because of my continued high fever, there was still no discernible cause.<\/p>\n It was a month before my temperature stabilised and I was able to be discharged. Recuperating at home I realised that my body\u2019s low resilience to stress after years of pushing myself to my limit had been to blame.<\/p>\n In addition to regaining strength, I prioritised rest, nutrition and movement, which I had long advised patients were essential but had ignored myself. I started with sleep. I set an alarm for 9.30pm to remind me to switch off screens before going to bed at 10.30pm and getting up at 6.30am. Back at work after four months off, I finally learnt to delegate. I filled up on protein and fibre, bought a standing desk, scheduled an appointment with myself at 12.30pm every day to go for a lunchtime walk or run and started lifting weights daily (I kept them under my desk at work).<\/p>\n As years passed and I felt stronger I realised there was more I could do to monitor my health than I\u2019d learnt at medical school. I could identify the key factors that influence our biological age and test for them.<\/p>\n