Nigeria is facing its worst economic crisis in decades, with skyrocketing inflation, a national currency in free-fall and millions of people struggling to buy food. Only two years ago Africa’s biggest economy, Nigeria is projected to drop to fourth place this year.

The pain is widespread. Unions strike to protest salaries of around $20 a month. People die in stampedes, desperate for free sacks of rice. Hospitals are overrun with women wracked by spasms from calcium deficiencies.

The crisis is largely believed to be rooted in two major changes implemented by a president elected 15 months ago: the partial removal of fuel subsidies and the floating of the currency, which together have caused major price rises.

A nation of entrepreneurs, Nigeria’s more than 200 million citizens are skilled at managing in tough circumstances, without the services states usually provide. They generate their own electricity and source their own water. They take up arms and defend their communities when the armed forces cannot. They negotiate with kidnappers when family members are abducted.

But right now, their resourcefulness is being stretched to the limit.

On a recent morning in a corner of the biggest emergency room in northern Nigeria, three women were convulsing in painful spasms, unable to speak. Each year, the E.R. at Murtala Muhammed Specialist Hospital in Kano, Nigeria’s second-largest city, received one or two cases of hypocalcemia caused by malnutrition, said Salisu Garba, a kindly health worker who hurried from bed to bed, ward to ward.