Western Front: illness, shell shock and new surgery

Trench fever was spread by lice living in soldiers' clothing. It caused high fever, headaches and aching muscles, and could put a man out of action for weeks. The link to lice was confirmed in 1918, and delousing stations were set up.
Trench foot came from standing for days in cold, wet mud. Feet swelled and could turn gangrenous, needing amputation. Prevention: dry socks, rubbing feet with whale oil, and regular foot inspections, so cases fell later in the war.
Shell shock was mental and physical breakdown caused by the stress of combat: shaking, nightmares, loss of speech or movement. Tens of thousands of British soldiers were affected; some officers were treated at Craiglockhart hospital in Edinburgh, but many men were seen as cowards.

The farmland of Flanders and France was heavily manured, so bacteria in the soil infected wounds, causing gas gangrene.
Surgeons cut away dead and infected tissue (debridement) or amputated.
The Carrel-Dakin method washed deep wounds with a steady flow of antiseptic solution through tubes.
Speed mattered, so more operations moved forward to Casualty Clearing Stations.

Brain surgery: the American surgeon Harvey Cushing used a magnet to draw metal fragments out of the brain and used local anaesthetic, which improved survival from head wounds.
Plastic surgery: Harold Gillies rebuilt the faces of men disfigured by wounds, using skin grafts and the pedicle tube; a specialist hospital opened at Sidcup in 1917.
X-rays: mobile X-ray units found bullets and shrapnel, though machines overheated and exposures were long.
These advances were limited by the knowledge of the time: there were still no antibiotics.