Swollen nostrils usually result from one of a few common triggers: a minor infection at the opening of the nose, an allergic reaction, environmental irritation, or physical trauma like nose picking. Most causes are easy to identify based on your other symptoms and resolve on their own or with simple treatment. Here’s how to figure out what’s going on and what to do about it.
Infection at the Nostril Opening
The most common reason for noticeable swelling right at or inside the nostril is nasal vestibulitis, a bacterial infection of the skin just inside the nose. It’s usually caused by Staphylococcus bacteria and produces redness, swelling, and tenderness around the nostril. You might also notice a pimple-like bump inside the nostril or on the tip of your nose, small bumps around the hair follicles, crusting, or even a boil. In more serious cases, the redness can spread to surrounding skin, and you may develop a fever.
This kind of infection typically starts after some kind of break in the skin. Pulling or trimming nose hairs, picking your nose, or blowing your nose too hard can all create tiny scratches that let bacteria in. Even a small nick can form a scab, and picking at that scab restarts the cycle, introducing more bacteria and damaging more of the nasal lining. People who carry staph bacteria in their nose (which is surprisingly common) are especially prone to this.
Once treated with a topical antibiotic ointment applied two to three times daily with a clean cotton swab, nasal vestibulitis usually starts improving within three to four days. If you notice mild soreness after pulling a nose hair or a small scratch, an over-the-counter antibiotic ointment can help. If swelling isn’t improving or is getting worse after one to two days of home treatment, it’s worth contacting your doctor.
Allergies and Blood Vessel Swelling
Allergic rhinitis is another major cause of nasal swelling, though it tends to affect the inside of the nose more than the visible nostril. When you inhale an allergen like pollen, dust, or pet dander, immune cells in your nasal lining release histamine and other inflammatory chemicals. Histamine acts directly on blood vessels in the nose, causing them to leak fluid into surrounding tissue and pool blood in specialized structures called capacitance vessels. These vessels can expand rapidly, which is why allergic congestion can come on so fast.
The nasal passages also contain three shelf-like structures on each side called turbinates. The lowest one sits just behind the nostril and can sometimes be seen from the outside when it swells. Turbinate swelling from allergies can be dramatic enough to block airflow entirely and create a visibly puffy appearance around the nostrils. In chronic cases, this swelling persists even after the allergen is gone.
If your swollen nostrils come with sneezing, a runny nose, itchy eyes, or a clear pattern tied to seasons or specific environments, allergies are the likely culprit. Over-the-counter antihistamines and nasal steroid sprays are the standard first-line approach.
Irritants and Weather Changes
Not all nasal swelling involves an allergic response. Nonallergic rhinitis causes similar congestion and swelling but is triggered by environmental irritants: dust, smog, cigarette smoke, strong perfumes, and chemical fumes. Changes in temperature or humidity can also trigger swelling in the nasal lining. If your nostrils swell up in certain rooms, around certain products, or when the weather shifts, but you don’t have the classic allergy symptoms like itchy eyes and sneezing, this is likely what’s happening.
The fix is straightforward: identify and avoid the trigger when possible. Saline rinses can help flush irritants from the nasal passages, and a warm, damp washcloth held against the face provides some relief from the pressure and swelling.
Pregnancy Rhinitis
If you’re pregnant and dealing with swollen, stuffy nostrils that won’t go away, pregnancy rhinitis is a common and underappreciated cause. Hormonal changes increase blood flow throughout the body, including to the nasal lining, causing persistent congestion that feels like a cold that never ends. It most commonly develops in the third trimester and typically resolves within two weeks of delivery. Saline sprays and elevating your head while sleeping are the safest ways to manage it.
Physical Trauma and Repeated Irritation
Sometimes the explanation is mechanical. A bump to the nose, aggressive nose blowing, frequent nose picking, or even wearing a CPAP mask that presses on the nostrils can cause localized swelling. The tissue inside and around the nostrils is thin and heavily supplied with blood vessels, so it doesn’t take much of a scratch to cause significant irritation. Repeated trauma creates a cycle: injury leads to scabbing, scabbing invites picking, and picking introduces bacteria that can turn simple irritation into a full infection.
If trauma is the cause, the swelling usually resolves within a few days once you stop the irritating behavior. Keeping the area moisturized with a thin layer of petroleum jelly can help the lining heal without cracking or scabbing.
Signs That Need Prompt Attention
Most nostril swelling is minor and temporary. But certain patterns suggest something more serious is developing. A rapidly expanding area of redness spreading from the nostril onto the cheek or upper lip can signal cellulitis, a skin infection that needs prescription antibiotics. If redness is spreading and you also have a fever, that warrants emergency care. A growing, painful lump inside the nostril that doesn’t respond to over-the-counter ointment within a couple of days could be a developing abscess that needs drainage.
Swelling limited to one nostril that persists for weeks, especially with bloody discharge, is worth getting checked. And if your nostrils are chronically swollen despite avoiding known triggers, the turbinates inside your nose may have become permanently enlarged, a condition that sometimes requires a procedure to reduce their size.