For more than 25 years, the NHS surgeon has volunteered in conflict zones from Sarajevo to Syria. In this extract from his book War Doctor, he recounts some of his most gruelling experiences • Read a Q&A with David Nott here

I have travelled the world for 25 years in search of trouble. It is a kind of addiction, a pull I find hard to resist. It stems partly from the desire to use my knowledge as a surgeon to help people who are experiencing the worst that humanity can throw at them, and partly from the thrill of just being in those terrible places, of living in a liminal zone where most people have neither been nor want to go: Afghanistan, Sierra Leone, Sudan, Chad, Liberia, Iraq, Libya, Haiti, Gaza and Syria, to mention a few.

Going to all those places has changed me, but none more profoundly than Syria. It was in Syria that I began to get seriously angry about the inability of the major powers to prevent hospitals and medical staff being targeted in war zones; in Syria that I realised I must begin seriously to collate and share the knowledge I had acquired over my career to help other doctors; and after Syria that post-traumatic stress disorder finally tipped me over the edge.

By the time I first arrived in east Aleppo with Syria Relief in August 2013, many of the more senior doctors and surgeons had already left. As many as 95% of the city’s physicians had found a route out. Those who remained were brave and committed, but there were very few of them and the risks were considerable. Clinics were assigned codenames to disguise how many there really were. Ambulances carried no sirens or insignia and at night drove with their headlights off. Anything that looked like help for the injured was seen as aiding the rebels, and so a legitimate target for the regime.

The hospital where I was based was close to the frontline, codenamed M1. The majority of injuries we saw were gunshot wounds. There were as many as 70 individual snipers dotted around east Aleppo at that time. They simply picked people off as they were crossing the street, going to work or going to the shops. From babies to pensioners, no one was immune.

Facebook Twitter Pinterest Nott on an early mission in Sarajevo, 1994. Photograph: Courtesy of the David Nott Foundation

On that first day alone in M1, 11 civilians shot by snipers were brought in. The doctors told me they had been losing a lot of patients with wounds to the major arteries; they needed significant training. I immediately agreed to give evening lectures, plus hands-on instruction for any surgeons who wanted it, where I could show my “best moves” – introducing them to new techniques, or little tricks such as how to hold their hands or instruments to save time on the table.

On that first day, all 11 patients who had been shot survived – but only after a solid 18-hour shift at the end of which I fell on to my bed absolutely exhausted. As the days went by, I noticed there was a weird consistency to the injuries we saw coming in – the patients all seemed to have been shot in the same part of the body. One day we would receive patients who had all been shot in the left groin area; on other days six or seven would arrive shot in the right groin. The same thing was happening with patients shot in the upper limbs and chest – the injuries all seemed to be on the same side, in clusters. Also, despite the snipers having telescopic sights, we rarely saw the head shots that would have resulted in an instant kill. Another surgeon told me that he’d heard that the snipers were playing a game: they were being given rewards, such as packs of cigarettes, for scoring hits on specific parts of the anatomy.

This sick competition reached its nadir towards the end of my time there when it appeared that one particularly vicious and inhumane sniper had a new target of choice: pregnant women. One such casualty arrived shot in the abdomen. The bullet had missed the baby but gone through the placenta. The woman was on the operating table only a few minutes after being shot and we delivered her baby boy via caesarian. I quickly clamped the cord and gave the infant to one of the nurses to resuscitate, but sadly she was unable to do so. We carefully sewed up the mother’s uterus in the hope that she would be able to have another baby; we weren’t going to let the sniper take that away from her.

Facebook Twitter Pinterest David Nott photographed at Chelsea and Westminster hospital. Photograph: Antonio Olmos/The Observer

The same day another sniper’s victim came into the hospital. She was a first-time mother, almost at full term. She was very beautiful, wearing an immaculate white headscarf and a long, elegant coat that now had a large red stain on the front. An abdominal X-ray showed that the bullet was still inside her abdomen, but appeared also to show, horrifically, that it was lodged in her unborn baby’s head. In the operating theatre, we performed a midline incision as quickly as possible and pulled the baby out. It was handed to a nurse as usual but it was pointless: the poor thing had a massive head wound and was obviously dead. The uterus was in tatters and we ended up having to give the mother a hysterectomy as well. This was probably the most upsetting and shocking act of violence I had ever witnessed against another human being.

A few days later, Ammar [a Syrian doctor who became a close friend] and I were grabbing an afternoon nap between operations when there was a knock on the door. Abu Abdullah [a Syrian surgeon] wanted to know whether I could help him with a thoracotomy. I dragged myself out of my slippery plastic bed and put on my operating shoes, which by this time were caked in dried blood – the floor was often awash with it. Once I got to the theatre I heard the patient had been shot in the back just below his shoulder blade. He was very pale under his thick beard and it was obvious that he was bleeding significantly.

Just as I was about to suture the pulmonary vein, the doors of the operating theatre burst open. I looked up and saw six fully armed men wearing black combat fatigues and headscarves storm into the room. They were Isis fighters, and the patient on the table was one of them. My heart lurched and I froze stock still. I felt a rush of adrenalin. The leader of the group came forward with his gun levelled at us.

“This is my brother!” he said aggressively, in English but with a very strong, Russian-sounding accent. Not just Isis, but Chechen Isis. “What are you doing to him?”

In English, Abu Abdullah told him that we were trying to save the man’s life.

“You should have asked us before taking our brother to surgery!” was the reply. “Who are these people?” he went on, indicating Ammar and me.

It was vital that I kept a low profile – I was almost certainly the only westerner in Aleppo at the time, and it would have been a major coup if I had been kidnapped. Ammar piped up in his strongest Syrian accent to say that we were all surgeons simply trying to save the man’s life. By this time I had begun to shake. It was all I could do to keep my legs from buckling under me.

“Who’s this?” he said, pointing to me. Abu Abdullah whispered in my ear, “Don’t say a word,” before turning back to the Isis leader and saying, “This is the senior surgeon. If you disturb him he will not be able to save your brother’s life.”

The leader came up to the operating table and peered into the man’s wound to see what we were doing. The rest of the group milled around the room menacingly – a few sat on the floor while others leaned on equipment and made themselves comfortable. It took us another hour to finish the operation. Usually, there is a lot of banter in the operating theatre but today we were silent. As we neared the end they all left, apart from the leader, who stayed until the last suture was in place. Afterwards, I found myself feeling confused and lost. I had saved the life of someone who might go on to commit terrible crimes. Did that make me complicit, somehow? Perhaps it did. And yet, I still firmly believe that it was my duty to save his life.

Back in London, I returned to my usual NHS work straight away – I rarely took any time off after a mission. But something was awry. I had had an extraordinary experience in Aleppo; my presence had made a clear and discernible difference, both while I was there and in the teaching legacy I had left behind. In London, there were any number of people who could carry out the operations I was doing. In the UK I might save one person’s life a month, whereas in Syria it had been 10 a day. What the hell was I doing here?

Facebook Twitter Pinterest In theatre in Bangladesh, 2017. Photograph: Courtesy of the David Nott Foundation

Home for me at that time was fairly spartan – a small flat overlooking the Thames. I had no family, my parents had both died several years before, and I had no other ties, no girlfriend. I was quite hard up, having sacrificed a lot of income to do my overseas work. I was disillusioned, bereft even. I realised I never felt so alive as I did on a mission, or so fulfilled in my job at home as I was abroad. I began seriously to consider packing in my NHS work in London and going overseas full-time.

Around this time, in July 2014, the Israel-Gaza war began. There was a lot at stake from a global political perspective. But from a humanitarian point of view it was yet again a dire situation for the civilians on both sides. I wanted to be immersed in what was going on. A week after the war started, my mobile rang. It was the International Committee of the Red Cross: would I go to Gaza City? That same day, I was on a plane to Tel Aviv.

I was embedded in the Shifa hospital in Gaza City, and quickly got down to work. It was pure, hardcore war-trauma surgery, mostly dealing with the effects of bomb-blast injuries. There was a mass-casualty event most days, and it became quite normal to receive something like 60 or 70 patients in extremis, suffering the effects of an airstrike.

One night I was woken at about one in the morning when my bed bounced off the floor. There had been an enormous explosion only metres away from the safe house where I was living. The hospital the next morning was bedlam. As I walked around assessing the injuries I came across a girl who looked about seven years old. She was lying on her own in the corner. She looked grey. I checked her vital signs: her airway was clear but her breathing was very shallow. She had a fragmentation wound to her left arm, which was bandaged, but that wasn’t all: her small bowel was hanging outside her body. This little girl was dying, and needed to go to theatre immediately.

I watched her being put to sleep and then went into the corner of the theatre to scrub up. Suddenly, the door of the operating theatre flew open. It was the hospital security manager. “We’ve got intel that says the hospital’s going to be attacked by shelling in five minutes. Everyone out.” Everybody began making a beeline for the door, joining the rest of the staff heading out of the hospital as fast as they could.

By this time, the little girl was asleep, and on the ventilator. She was a pitiful sight. The time she had left to live could be counted in minutes, not hours, whether there was an airstrike or not. Lots of things went through my mind. The most burning thought was that I could not leave this little girl to die on her own. I had thought I might die during the shell attack on the safe house the previous evening. But maybe this was the moment it ended. And if it was, did I need to save myself? The answer, of course, was no. I was on my own in the world. In the grand scheme of things, it didn’t much matter whether I lived or died. I made a conscious decision to stay.

I turned to Mauro, the anaesthetist, and said, “You can go, you don’t need to stay.”

“Are you staying?”

“I’m staying.”

“Then I’ll stay with you.”

He, too, was a veteran of many missions, also unmarried with no dependants. I suppose we had both been thinking the same thing. So we stayed with the little girl, waiting for the bomb to drop or the missile to strike. I prepared her abdomen with iodine, picked up the green drapes and clipped them into position. I made an incision the full length of her abdomen. Inside was a large piece of shrapnel that had caused mayhem. The familiar process of operating took my mind off the situation we were in, and by the time I’d removed her spleen Mauro told me 20 minutes had passed. Still no attack. We completed the operation, repairing the holes in her small bowel and colon, and making her abdomen look normal again. I then turned my attention to her left arm.

Facebook Twitter Pinterest David Nott at an outdoor clinic in Darfur, 2005. Photograph: Courtesy of the David Nott Foundation

Two hours later, the theatre was still deserted. We decided to wake her up. As we were doing this, people started to drift back in, amazed to see us still there. Clearly, there was to be no attack. I am not sure where the information had come from but I was told that it was a credible source and that’s why everybody had panicked and left. Nor do I know how many patients died in other operating theatres. I only knew that our little girl was alive. I went to see her every day after that, and got to know her family well. Her name is Aysha and the photograph I have of me standing by her hospital bed, both of us smiling, says it all.

While in Gaza, I really thought there was a very strong possibility that my time might finally be up. I remember one night spent in the bunker – a concrete underground room, its entrance surrounded by sandbags – during a bombing raid. About 15 of us sat through what sounded like the coming apocalypse. I had never before experienced such intense military action, not even in Iraq or Afghanistan. Many people were crying.

As I got changed and packed my bag the next morning, a business card fell on to the floor. It carried the name of a young woman I had met just before coming to Gaza, at a Syria Relief fundraising event. Her name was Elly. Her email address was on the card and, as I looked at it, I realised she was the one person I wanted to talk to. I decided to email her. It seemed random enough that it wouldn’t matter if she ignored my message; but I admit that, although we had only met for a few minutes, she had made my heart miss a beat. I quickly wrote a short email saying how much I liked her, pressed “send” and went to work.

Elly agreed to meet me for a drink in London. We arranged to meet on the day I got back from Gaza. But, once home, I began to regret the suggestion – I was shattered, and my mind was elsewhere, in a land full of bombs and bullets and damaged limbs. In the restaurant we were surrounded by people laughing and having a good time, but I was finding it difficult to adapt to the fact that I wasn’t somewhere I might be blown up at any moment and was sitting opposite someone I’d only emailed because I’d thought that I was going to die. It seemed an inauspicious way to begin whatever this was, or might become. I had always longed for a partner, maybe even a family, but had simply not met the right person and was barely in one place long enough to do so. Maybe this would be the final roll of the dice. I sipped my glass of red wine and decided to stay. By the end of the meal I was in love. It was as simple as that. And for the next few weeks we were inseparable. But separation loomed: I had promised to go back to Syria.

As I left Elly at the departure gate at Heathrow, I promised her that I would be back to see her soon. But part of me didn’t believe that and thought the mission to Syria would be my last. Not because I no longer wanted to volunteer, but because I was not sure I would survive. When we reached the outskirts of Aleppo, the difference from the previous year was immediately visible. Where in 2013 there had been shops, markets and people, now there was only destruction on an industrial scale. We could see dozens of cars, trucks and lorries on the side of the road, some completely destroyed and others bearing the scars of rocket attacks. I was certain bodies must still be inside the wreckage of the vehicles. It was like something out of a Mad Max movie.

I noticed the atmosphere in the hospitals and among my colleagues was quite different: tense, charged. It felt altogether edgier and more dangerous than my previous trip. The doctors looked drained, hollow. They were under constant barrage from barrel bombs, rockets and machine guns. Simply getting around the city had become exceptionally dangerous. The chance of being killed simply moving from one hospital to another was something like one in four. One of the new doctors helpfully told me my chances of leaving Aleppo alive were 50/50.

Facebook Twitter Pinterest David Nott and Aysha, the girl whose life he saved in Gaza City. Photograph: David Nott Foundation

I had a near-constant pain in the middle of my chest, which I could ignore only when I was immersed in an operation. Day after day we saw entire families brought in to the hospital, their homes destroyed by barrel bombs. Most of the children we saw were under 10. Some were dead on arrival, from the effects of the shockwave or from inhaling pulverised concrete. One particular day will stay with me for the rest of my life. Following a colossal bang, a family of seven children came in with their dead mother. The first child was just a toddler, and had lost both her feet. Her brother on the next trolley was about seven – he had a massive pelvic injury. Another boy, about the same age, had blood streaming from his face. I still have nightmares about what happened next. A little boy, about five years old, was brought in, face down on the trolley. Both his buttocks and the backs of his thighs had been completely blown off. He was still alive but completely silent as he gazed around the room. One of the nurses pulled his hair back from his face and started to comb it gently with her fingers. That was all we could do for him; we had run out of morphine. A few minutes later another child was brought in, his sister. Half of her head and brain were missing.

On our last day, we heard the sound of heavy gunfire outside the house. I peered through a crack in the window and could see about 20 armed men coming towards us, some walking and firing their weapons, others with heavy-calibre machine guns on the back of pickup trucks. I began to panic. I was cold and clammy and began shaking uncontrollably. Had Isis finally caught up with me? We hit the deck, hiding under our beds. I closed my eyes and lay there, in despair – for myself, and for this poor country that had been overwhelmed by darkness. The shooting lasted around an hour. At some point the hospital administrator told me not to worry – the fighting was just between two rival Free Syrian Army factions. It turned out later he had hidden the reality of the situation to protect me. The fighters were Isis, and it was their last chance to take me hostage.

Back in London, I returned to normality. Except things weren’t normal. I was exhausted from the physical work, and brutalised by the psychological trauma of seeing so much suffering. It was probably not the most sensible time to be doing a private outpatients’ session – the problems I was dealing with in my room off Sloane Square all seemed pointless and trivial. I nodded my way through, on autopilot, but by mid-afternoon I could feel myself getting ever more tense and angry.

My final patient came in. She was very, very unhappy that she had had to wait for six weeks to see me, and very, very disappointed that I did not seem to care that she had been made to wait. She began talking about her thread veins, which again seemed utterly trivial. As she was talking all I could hear was a roaring in my ears and the tension in my body rose until I couldn’t take it any longer. I suddenly stood up and screamed as loudly as I could. She looked at me in astonishment and left. I sat on my consulting room chair for the next three hours just staring at the ceiling.

I was not well.

My diminishing ability to cope was rather spectacularly exposed a week later, when I was invited to a private lunch with the Queen at Buckingham Palace. The contrast between those gilded walls and the ravaged streets of Aleppo began doing weird things to my head. I was sitting on the Queen’s left and she turned to me as dessert arrived. I tried to speak, but nothing would come out of my mouth. She asked me where had I come from. I suppose she was expecting me to say, “From Hammersmith,” or something like that, but I told her I had recently returned from Aleppo. “Oh,” she said. “And what was that like?”

Facebook Twitter Pinterest David Nott with his wife Elly. Photograph: Annabel Moeller

My mind filled instantly with images of toxic dust, of crushed school desks, of bloodied and limbless children and of David Haines, Alan Henning and those other western aid workers whose lives had ended in the most appalling fashion. My bottom lip started to go and I wanted to burst into tears, but I held myself together. She looked at me quizzically and touched my hand. She then had a quiet word with one of the courtiers, who pointed to a silver box in front of her, which was full of biscuits. “These are for the dogs,” she said, breaking one of the biscuits in two and giving me half. Together, we fed the corgis. “There,” the Queen said. “That’s so much better than talking, isn’t it?”

While an embarrassing scene had been averted, it did not change the fact that I was not well. I found myself being aggravated by the smallest things, arguing about nothing. I felt detached from the world around me. My behaviour became increasingly irrational. I flew into rages and suffered from a persistent sense of desperation. I would lie on the floor in a foetal position, unable to move, observing myself as if from a distance and watching Elly become more and more distraught. I was confrontational and critical of every aspect of her character. This went on for days and I almost lost her. Somehow, despite the depths of my psychosis, I knew that I had to talk to someone, and I went to see a psychiatrist I knew. He was very helpful, not only listening as I unburdened myself for hours, but also offering some tough love.

It’s tempting to think of my breakdown as being caused by the cumulative effect of the stresses I had experienced over the years – the brushes with death, the danger, the constant emotional assault of seeing innocent people and children suffer. But I’d always been able to move on in the past. What was different now? Was it that the past year had been particularly difficult, culminating in that brutal mission to barrel-bombed Aleppo? Perhaps. But I think the main difference was Elly. Before, I had nothing to come back to; now, I did – and, in some ways, it was terrifying. There was so much more at stake.

With help, I began to deal with my problems. I had a course of cognitive behavioural therapy and antipsychotic drugs were mooted, although in the end they proved unnecessary. With Elly’s patience and forbearance, I was rescued from myself.

David Nott is now married to Elly and they have two small daughters, Molly and Elizabeth Rose

• This is an edited extract from War Doctor: Surgery on the Front Line by David Nott (Picador, £18.99). To order a copy go to guardianbookshop.com or call 0330 333 6846. Free UK p&p over £15, online orders only. Phone orders min p&p of £1.99