Due to the widespread death and destruction during the war, the exact number is not known. However, the general consensus is that around 4 million people died from war related causes.

In regards to your question about how Vietnam absorbed those losses, the answer is simple. Vietnam may be small on a map, but it has a large population. Back in 1975, when the war ended, Vietnam had a population of around 50 million people. In comparison, the U.S. had around 200 million at the time. Today, Vietnam’s population is just shy of 100 million.

We must also remember that Vietnam was divided at the time. North Vietnam (with the support of the USSR and PRC) was fighting South Vietnam (backed by the USA). So in a sense, it was a civil war, which lead to the high casualty counts.