What is known about Reginald Henderson's death?

What killed Rear Admiral Reginald Henderson?

The exact cause is uncertain, but his family and the surviving work record point to severe overwork during the Royal Navy's prewar preparations.

The exact medical cause of Rear Admiral Reginald Henderson's death is not established in the sources discussed here. Henderson and his wife had been working exceptionally long days as he pressed the Admiralty's rearmament and shipbuilding case before the Second World War. Even after becoming ill and entering hospital, he continued handling correspondence until he was ordered to stop. The uncertain diagnosis should be kept separate from the well-attested evidence of his exhausting official workload.