Life expectancy is a snapshot of mortality, not a personal expiry date

The headline life-expectancy figure usually combines the mortality rates observed at each age during one period. It asks how long a hypothetical population would live if those rates remained fixed throughout life.

That is different from following people born in a particular year until their actual deaths. Their experience may include decades of improving or worsening health conditions. A period measure can therefore change sharply during a crisis without predicting that every newborn will face that crisis forever.

It is also an average. High childhood mortality can pull the figure far below the ages commonly reached by people who survive childhood. This explainer gives a practical way to read historical and international comparisons without confusing a useful population statistic with an individual forecast.