Rib Clicking Under the Breast: When Costal Margin Instability Imitates Heart, Lung, or Gallbladder Pain

Costal margin instability is a mechanical problem in the lower rib cage where one of the ribs near the costal margin (the curved arch you can feel under the breast and along the upper abdomen) moves more than it should. This extra motion can pinch the nearby intercostal nerve and inflame the surrounding soft tissue, creating sharp, stabbing chest wall pain on one side. Many clinicians refer to this pattern as slipping rib syndrome, interchondral subluxation, rib tip syndrome, or clicking rib syndrome. All of those labels describe the same core issue: an unstable lower rib that is slipping or subluxing against the rib above it. ^[1]

Here is what that really means in plain language: your rib is not “broken,” but the cartilage connection that normally holds the lower ribs steady has loosened or stretched. When that happens, the rib end can move, catch, or “pop,” especially with twisting, coughing, deep breathing, laughing, or rolling in bed. That sudden shift can feel like a knife under the breast, followed by a throbbing or burning ache that wraps around toward the side or even into the back. ^[1]

Costal margin instability is underdiagnosed. It is frequently mistaken for gallbladder disease, stomach problems, costochondritis, anxiety-related chest pain, or even a heart scare, because the location is so close to the chest and upper abdomen. Many people are told “your heart and lungs look fine” and sent home with no real explanation for why their rib still clicks. ^[1]

To understand the pop, you need to understand how the lower ribs attach.

Ribs eight, nine, and ten are sometimes called the “false ribs.” Unlike the upper ribs, they do not hook directly into the breastbone. Instead, they attach to each other through flexible cartilage bands. Those cartilage bands act like a suspension bridge between ribs. If that band stretches, tears, or becomes lax, one rib tip can slide or pivot over the rib above it. ^[1]

When the rib tip shifts, three things can happen:

1. The rib tip can physically bump or scrape against the rib above it, which creates the audible or tactile “click.”
2. The intercostal nerve that runs along the underside of the rib can get pinched or irritated, which causes the sudden stabbing pain people describe as “like someone jabbed me with an ice pick.” ^[1]
3. The surrounding muscles and soft tissues can become inflamed, leading to a lingering burning ache or bruised feeling even after the pop is over. That aching pain can spread into the upper abdomen or wrap toward the flank or back. ^[1]

Because this is a mechanical slip and not an infection or a fracture, standard chest X-rays and even computed tomography (CT) or magnetic resonance imaging may look “normal” if the rib is not actively slipping at the moment of the scan. That is one major reason people go in with dramatic pain and leave with “no findings.” ^[1]

Most patients describe the same cluster of symptoms in slightly different words. These symptom patterns are extremely helpful for search intent and also for diagnosis:

1. Sudden knife-like pain under one breast or along one lower rib.

   The pain is usually on one side, not across the whole chest. It often hits at the lower edge of the rib cage, right where a bra band or seatbelt might sit. People often say, “It hit in one exact spot and took my breath away.” ^[1]

2. Popping or clicking you can feel with your fingers.

   Many patients can reproduce the click by pressing on the tender spot or bending a certain way. Some can literally feel something move out of place and then snap back. That mechanical click is a huge clue that this is costal margin instability and not heartburn, pleurisy, or heart pain. ^[1]

3. Burning, tingling, or electric pain that wraps around to the back.

   After the initial stab, there may be nerve-type pain that travels along the same rib toward the side or even into the back. That is because the intercostal nerve runs in a curve under the rib and gets irritated when the rib slips. ^[2]

4. Worse with twisting, coughing, laughing, or rolling in bed.

   Deep breathing, sneezing, sit-ups, swimming strokes, certain yoga twists, or even just reaching for a seatbelt can trigger the pop. Many people say the worst flare they ever had happened when they rolled over in bed or tried to get out of bed. ^[1]

5. Fear that it is a heart attack, gallbladder attack, or collapsed lung.

   Because the pain is so sharp and so sudden in the chest and upper abdomen, people understandably panic. Emergency screenings for heart attack, pulmonary collapse, and gallbladder inflammation may all be normal, which is both reassuring and frustrating if you still cannot sleep, twist, or lift a child without feeling like your rib is tearing. ^[1]

A lot of people with rib pain are told they have costochondritis. Costochondritis is inflammation where the upper ribs meet the breastbone. It usually causes soreness and tenderness in multiple upper ribs near the center of the chest, and those joints can be swollen in a condition called Tietze syndrome. ^[3]

Costal margin instability is not that.

Costal margin instability usually lives lower, near the eighth, ninth, or tenth ribs — under the breast and along the upper abdominal wall. Instead of just feeling sore to the touch, it often comes with an actual click or pop because the rib end is moving. Instead of being spread across several ribs, it is often one exact rib and one precise spot. Instead of just being achy, it can feel like a violent stab that steals your breath for a second. ^[1]

This distinction matters, because a mislabel of “costochondritis” can delay the right treatment. Costochondritis is usually treated like an inflamed joint. Costal margin instability often needs stabilization and sometimes nerve-focused care.

There is usually one of three paths into this problem:

1. Micro-injury or trauma to the rib attachment.

   A fall onto the side, a sports collision, sudden violent coughing, or seatbelt force in a traffic incident can stretch or tear the fibrous bands that normally hold the rib tip in line. Contact and twisting sports like wrestling, rugby, throwing sports, swimming, and baseball pitching are commonly described in case reports and clinic summaries. ^[4]

2. Repetitive twisting, bending, or overhead reach.

   Even without a single big injury, repeated side-bending under load can fatigue the ligament-like structures that stabilize the false ribs. Occupations or gym routines that involve a lot of trunk rotation, forceful reach, or abdominal straining (for example, weighted sit-ups with a twist) can slowly loosen the costal margin. ^[5]

3. Baseline ligament laxity.

   Some people are naturally more flexible in their joints and connective tissues. When your ligaments are a little looser everywhere, the costal cartilage connections that are supposed to keep the rib tips aligned may not hold as firmly, making you more likely to develop a hypermobile rib that slips. 

Costal margin instability can show up in adults, teenagers, and even children. It has been documented in patients as young as seven years old and as old as the eighties, and it tends to appear slightly more often in females and in middle-aged adults. ^[2]

There is no single blood test for this condition. Diagnosis is mostly clinical — which means it depends on a careful story plus a hands-on exam from someone who knows what to look for.

1) The symptom story

If you say, “I get a sharp stab under one breast when I twist or cough, and sometimes I feel or hear a click in that exact spot,” most specialists who have seen costal margin instability will already be thinking about a hypermobile lower rib. That combination of one-sided popping plus stabbing pain with motion is highly suggestive. ^[1]

2) The hooking maneuver

The hooking maneuver is considered the classic bedside test. The clinician gently slides their fingers under the costal margin at the painful rib and lifts upward and outward. If that reproduces your trademark pain or even recreates the slip or click, the test is considered positive. Many patients will say, “That is exactly it,” the instant the rib is lifted. ^[6]

This maneuver works because it mechanically challenges the unstable rib segment. When that segment moves too far, it irritates the nerve and soft tissue in the same way that daily movements do.

3) Dynamic ultrasound imaging

Standard X-rays cannot see the cartilage well and often look normal. Computed tomography and magnetic resonance imaging may also miss the instability if the rib is at rest. A targeted dynamic ultrasound, done while you cough, crunch, or twist, can sometimes capture the rib tip actually sliding or subluxing under the rib above it and irritating the intercostal nerve. ^[1]

This is powerful for two reasons: it visually confirms that you are not imagining it, and it helps guide treatment (for example, where to inject a nerve block).

4) Relief from an intercostal nerve block

In some clinics, the clinician may inject a small amount of local anesthetic around the irritated intercostal nerve near the unstable rib. If the classic pain disappears right after the injection, that strongly supports costal margin instability as the true source. These same injections can also help calm an angry nerve and break the pain cycle. ^[6]

Costal margin instability hurts a lot, and it can absolutely reduce quality of life. People with this condition often stop exercising, sleep poorly because rolling in bed sets it off, and even change how they breathe because deep inhalation is scary. ^[1]

But in most cases it is not a heart attack, a collapsed lung, or a tumor. It is mechanical nerve irritation from a moving rib end.

That said, you should still treat first-time sudden chest pain or trouble breathing as urgent until a qualified clinician rules out emergencies like heart attack, blood clot in the lung, or lung collapse. Crushing central chest pressure, chest pain with jaw or arm spread, coughing up blood, fever with shortness of breath, or faintness demands immediate in-person care. Chest pain is never something to self-diagnose the very first time. ^[1]

Treatment depends on how severe the symptoms are, how often they flare, and how much they limit daily function. Care usually starts conservatively and only moves toward procedures or surgery if the pain keeps coming back.

Step 1. Protection and symptom control

Short-term rest from high-twist activities, bracing or taping to limit motion at the painful rib tip, and anti-inflammatory strategies (ice during an acute flare, gentle heat for muscle guarding later, guided use of non-steroidal anti-inflammatory medication if medically appropriate) can calm down the irritated nerve and soft tissues. This phase is about getting you sleeping and breathing again without sharp jolts. ^[1]

Step 2. Focused physical therapy for rib stability

A skilled physical therapist can retrain how you load your trunk so that you stop yanking on the unstable rib segment every time you twist, sit up, or reach. This is not “just strengthen your abs.” Aggressive sit-ups can actually trigger a flare. Instead, the work is usually controlled breathing mechanics, deep core stabilizer training, postural correction, and gradual, guided rotation drills that respect the healing rib. Restoring healthy motion in the upper and mid back can also take pressure off the vulnerable costal margin. ^[5]

Step 3. Intercostal nerve block or steroid injection

If pain stays severe, an ultrasound-guided injection around the irritated intercostal nerve can quiet the inflammation, allow normal movement patterns to resume, and confirm that the slipping rib region is truly the pain generator. Some clinicians also add a small steroid dose to extend relief. ^[6]

Step 4. Stabilization or reconstruction procedures

For chronic, disabling cases that do not respond to conservative care, surgical options exist. One common approach is trimming or removing the unstable rib tip so it can no longer sublux and pinch the nerve. Another evolving approach is costal margin reconstruction, in which the surgeon repairs and stabilizes the loose costal cartilage connections to restore a stable arch. Early reports suggest that surgical stabilization can produce long-lasting pain relief and allow people to return to normal activity, often without the fear of the next “pop.” ^[1]

Most people will never need surgery. But it matters to know it exists, because patients with severe costal margin instability are often told for years that “nothing is wrong,” when in fact there is a fixable mechanical problem.

Here is language that tends to get attention and leads to the correct physical exam:

• “I keep getting a sudden stabbing pain under one breast or at the lower edge of my rib cage on one side. It takes my breath away.”
• “I sometimes feel or even hear a click or pop in that exact spot.”
• “It gets triggered by twisting, rolling in bed, coughing, or reaching for a seatbelt.”
• “After the pop, I get a burning pain that wraps around toward my back along the same rib.”
• “The emergency room ruled out heart and lung causes, but the pain is still reproducible right here. Can you check if this rib is moving too much? I read about costal margin instability and slipping rib syndrome.” ^[1]

This script does two things. First, it clearly says “one rib, one spot, mechanical click.” Second, it signals that you are aware of costal margin instability as a real diagnosis. That often prompts the clinician to perform the hooking maneuver instead of just ordering another basic scan.

• Rib popping or clicking under the breast with sharp one-sided chest wall pain is not always heart, gallbladder, stomach, or panic.
• Costal margin instability (commonly called slipping rib syndrome or rib tip syndrome) happens when a lower rib becomes hypermobile at its cartilage connection and irritates the intercostal nerve. ^[1]
• The pain can be intense, sudden, breath-stealing, and followed by burning or tingling that wraps around the side. It is often triggered by twisting, coughing, laughing, or rolling in bed.^[1]
• Standard X-rays and even computed tomography can look normal because the problem is mechanical instability, not a fracture, and the rib might not be slipping during the scan. ^[1]
• Diagnosis is often made in the clinic with the hooking maneuver and can be supported by dynamic ultrasound imaging done during movement. ^[6]
• Treatment ranges from rest and rib stabilization strategies to targeted intercostal nerve blocks and, in stubborn cases, surgical reconstruction of the costal margin. Many patients regain normal activity and finally stop guarding every movement. ^[1]

If you have this exact pattern — one-sided rib popping, clicking under the breast, stabbing pain that comes with a twist — you deserve to have someone examine that rib, not just your heart tracing.