The European single currency hit exactly one dollar -- its lowest level since December 2002 -- before rising to $1.0023 in Tuesday trading.
"The gas crisis has really spooked markets over the eurozone economy," Markets.com analyst Neil Wilson told AFP.
The European single currency is also under pressure from the Federal Reserve hiking US interest rates more aggressively than the European Central Bank.
The dollar has jumped 14 percent against the euro since the start of the year.
As for the gas-propelled pressure, Russian energy giant Gazprom on Monday began 10 days of maintenance on its Nord Stream 1 pipeline -- with Germany and other European countries watching anxiously to see if the gas comes back on.
With relations between Russia and the West at their lowest in years because of the invasion of Ukraine, Gazprom may not reopen the valves, according to analysts.
"The next few weeks could be challenging for Europe, with possibly maximum uncertainty stretching into August," said SPI Asset Management's Stephen Innes.
Worries about a Covid flare-up in China -- fueling fears of more lockdowns -- added to the downbeat mood, just as investors prepared for a week of economic data and corporate earnings that could have huge implications for markets.