This question arrives a day or two before departure, and the honest answer is that it depends on how congested you actually are.

Flying with a mild cold is something most people do without consequence. Flying while genuinely blocked is a different proposition, and it's worth understanding why before you decide.

Why congestion changes the calculation

During descent, cabin pressure rises faster than your middle ear can keep up with. Equalizing requires the eustachian tube to open and let air in — and unlike venting outward on ascent, which happens fairly passively, letting air in on descent takes active effort from a tube that's working properly.

A congested tube is swollen at exactly the point where it needs to open. So the pressure difference across the eardrum keeps building with nowhere to go. That's what produces the fullness, then the muffling, then the pain — and in the worst case, fluid drawn into the middle ear or a perforation.

The risk isn't theoretical, but it also isn't uniform. A slightly stuffy nose and a head cold that's blocked you solid for three days are not the same situation.

A rough way to judge

Can you breathe through both nostrils reasonably well right now? Can you make your ears pop deliberately, using a gentle Toynbee or Valsalva? If both are yes, you're in reasonable shape, and the guidance in why your ears hurt on airplanes will serve you.

If you cannot pop your ears at all on the ground, that's the finding that gives me pause. On the ground you have unlimited time and no pressure gradient. At thirty thousand feet descending, you have neither.

Add to the caution list: an active ear infection, a known perforation, recent ear surgery, or a sinus infection with facial pain. Those warrant a conversation with your own physician before flying rather than a strategy for coping with it.

Flying more safely if you're going anyway

Start before you board, not during descent. Whatever you're using for congestion works better with a head start.

Talk to a pharmacist or your provider about a decongestant. Oral decongestants and nasal decongestant sprays both have a role, and both have caveats — sprays cause rebound congestion if used more than a few days, and oral decongestants aren't suitable for everyone, particularly with hypertension or certain heart conditions. This is worth thirty seconds of actual advice rather than guessing.

Saline, generously. Cabin air is extremely dry, and dried secretions equalize worse than moist ones.

Stay awake for descent. You don't swallow often enough asleep, and descent is the dangerous half.

Equalize early and often. Start gently as soon as descent begins, every few minutes, rather than waiting for discomfort. Catching up is much harder than keeping up.

Consider pressure-regulating earplugs. They slow the rate of change and help some people meaningfully.

Skip the alcohol. It dehydrates and worsens congestion.

The children question

Children have shorter, more horizontal eustachian tubes that equalize less efficiently, which is why they're the ones crying on descent. A congested child has a genuinely harder time than a congested adult. Feeding an infant during descent prompts swallowing; older children can drink through a straw.

If a child has an active ear infection, ask your pediatrician before flying rather than working it out at the gate.

When I'd reconsider the trip

If you're solidly blocked, can't pop your ears at all, and the trip is genuinely flexible, delaying a day or two is reasonable. Most trips aren't flexible, which is why the mitigation above matters more than the ideal.

Afterwards

Most ear pain from flying settles within hours. See someone if you have hearing loss that persists more than a day or two, ongoing significant pain, drainage or bleeding, or severe vertigo. If your ears feel blocked for weeks afterward, that's fluid in the middle ear, and it's worth having looked at rather than waited out — ear pressure that won't go away covers what that involves.

FAQ

Will chewing gum be enough?

It helps by prompting swallowing, but it doesn't address a swollen tube. Treat the congestion as well.

Are pressure-regulating earplugs worth it?

Inexpensive, low-risk, and some travelers find them genuinely useful. Reasonable to try.

Can flying congested cause lasting damage?

Uncommonly. Barotrauma usually resolves. Perforation and persistent fluid do happen and are the reason for the caution.

What about scuba diving with a cold?

Don't. The pressure changes are far greater and the stakes are higher. Wait until you're clear.