I have just come to the end of another long weekend as the haematologist on call. They are tiring, challenging days. We can be called about anything, anytime from paediatrics to geriatrics, from surgery to maternity.  Some calls will make me sit bolt upright in alarm, others will barely scratch the protective crust I have developed since starting on call rotas in 1992.

On call for me now means an extra 16 hours of availability at the end of my working day, followed by another working day. Or, the entirety of the weekend is bookmarked by the full working days of Friday and Monday, 80 hours in a row. It feels like an eternity. I will do 5 of these weekends a year as we share the shifts among the team. I get a 3% supplement to my salary for being on call from home.

Just knowing I might get called is usually enough to ensure I will not sleep properly.

I might not get called every time I am on call, but I frequently do. Just knowing I might get called is usually enough to ensure I will not sleep properly. Our Trust switchboard team is lovely. They always say hello, always ask if I am ok to take the call, and if it’s the middle of the night, they just give me those few moments it takes to engage my brain into first gear. I owe them a lot for that.

We seem to receive a surge of calls between 5pm and 7pm. It is the time of the day when people are reviewing results, maybe their first chance to sit down and do a bit of thinking. A call at this time is often opened with a “hello, can I give you an NHS number?” The assumptions being made make me realise that many people don’t know what our on calls are like, where we do them or how we work. People must be picturing me sitting next to my PC, pen in hand, the lab result browser open, logged in and ready to go.

Between 5pm and 6pm there is a high chance I will be cycling home. I have a special pair of bone conduction headphones that allow me to take a call when I am on my bike. I don't like to miss any calls. I can still sense the world around me with these headphones and as most of my journey home is on quiet paths, I usually just slow down and chat through the query rather than pulling over. It’s a good icebreaker, explaining the bird song or the noisy ruffle of wind on the microphone.

If I am lucky, a 3am call is a quick agreement about a plan. If I am unlucky, it is a highly complex situation requiring deep thought or review of a blood film.

Calls through the rest of the evening have similar issues. I have to shower when I get home, I have to eat, I have to pee, I have to walk the dog, I have to sleep. I could be called at any time, and they are usually highly complicated questions. My contract does not demand I stay awake, next to a computer! These on-calls are very different shifts compared to those of our resident doctors. They are very much plugged in every single moment. I have done those sorts of shifts, I have been resident on call, done the night shifts, the partial shifts, the lot. I will not reminisce fondly about any of them. There were times I didn't see my wife or children for days. My wife, in many ways, is still on call with me even now. She is disturbed by the night time calls as much as me.

If I am lucky, a 3am call is a quick agreement about a plan. If I am unlucky, it is a highly complex situation requiring deep thought or review of a blood film. I might need to go in for some of those patients. Strangely though, what can be even worse are the truly pointless phone calls. The call that could have waited, the question better answered by someone else, the call that doesn't appear to have any purpose I can discern.

You might wonder why these ones bother me most. It is because of their impact, I have to work the next day. I have to be fully ready and able to see many more patients. I need to go back to sleep!  It is almost impossible for me to switch off if I let these calls bother me. I try very hard to “let it go”, but that can be difficult at 3am after a call about an unlabelled sample or a question about tomorrow's blood transfusion. I understand why people call, I know a simple “yes” can be very reassuring, I know it can be impossible to know what can and can not wait. I have 30 years of experience doing this, most of the decisions are straightforward for me -  that's what I am here for. So I try to see every call as an investment. Another person will know what to do next time. I am on call to keep things calm and sensible, to respond when needed and to direct the team who are closer to the patient than me. On calls are hard, they unsettle, they loom and they seem to go on forever.

But do keep calling me, call me with those questions. Have the story ready. Give me a moment to wake up if it's late. Tell me what you need - advice, reassurance, answers, a decision or to come in. Check and see if there is already a policy for what to do, see what might be useful to have to hand and have the notes and lab results nearby. Just know I am not next to a computer, I might be asleep needing to work the next day or I might be cycling home, from here to maternity.