What Kind of Shoulder Pain Is Associated With Ectopic Pregnancy?

The shoulder pain linked to ectopic pregnancy is a sharp, referred pain felt at the tip of the shoulder, triggered when blood from a ruptured ectopic pregnancy pools against the underside of the diaphragm and irritates the phrenic nerve. Clinicians call this phenomenon Kehr’s sign, and it is widely regarded as a red-flag symptom suggesting that a rupture has already occurred. The pain feels nothing like a pulled muscle or a stiff joint, and understanding what distinguishes it can be genuinely life-saving.

Why a Problem in the Pelvis Causes Pain in the Shoulder

An ectopic pregnancy develops outside the uterus, most often in a fallopian tube. If it grows large enough to rupture, blood spills into the abdominal cavity. Because the abdomen is a closed space, that blood can travel upward and collect beneath the diaphragm, the dome-shaped muscle separating the chest from the abdomen. When blood irritates the underside of the diaphragm, it stimulates the phrenic nerve, which runs from the neck (cervical spinal nerves C3 through C5) down to the diaphragm. Your brain interprets signals from the phrenic nerve as coming from the shoulder region, because the same spinal nerve roots also supply sensation to the skin over the shoulder tip. The result is referred pain: you feel it in your shoulder even though the actual problem is in your abdomen.

A case report of a rare diaphragmatic ectopic pregnancy documented a 34-year-old woman who presented with right upper abdominal pain accompanied by right shoulder pain, described as Kehr’s sign, which the authors highlighted as a crucial diagnostic clue for upper abdominal ectopic pregnancy.¹ This referred-pain mechanism is the same reason that free air or blood under the diaphragm from other causes, such as a ruptured spleen or post-surgical gas, can also produce shoulder tip pain. In the specific context of a woman of reproductive age with pelvic symptoms, shoulder tip pain raises immediate suspicion for a ruptured ectopic.

What the Pain Actually Feels Like

The shoulder pain from an ectopic pregnancy does not resemble the dull ache of a strained rotator cuff or the stiffness of a desk-related neck problem. It is typically described as sharp, sudden, and located specifically at the tip of the shoulder, where the shoulder meets the arm, rather than deep in the joint or across the top of the trapezius muscle. One of the earliest clinical descriptions, published in JAMA in 1923, recorded a patient reporting “severe darting pains in the shoulders” that began two days before hospital admission and followed an episode of fainting.² That word “darting” captures what many patients describe: a stabbing quality that comes in waves or flares rather than a constant background ache.

A few features help distinguish it from ordinary shoulder problems:

Location: at or very near the shoulder tip, not deep inside the joint or radiating down the arm.
No positional relief: moving your arm, stretching, or lying in a different position does not ease it. Musculoskeletal shoulder pain usually shifts with position; referred pain from diaphragmatic irritation does not, because the source is internal.
No history of injury: the pain appears without any preceding trauma, overuse, or change in activity.
Context of other symptoms: it tends to arrive alongside lower abdominal or pelvic pain, vaginal bleeding, dizziness, or a missed period.

If the pain can be reproduced by pressing on the shoulder or by raising and rotating the arm, it is more likely musculoskeletal. Referred pain from diaphragmatic irritation is not tender to the touch at the shoulder itself, because nothing is wrong there structurally.

Which Shoulder, and Does It Matter?

People sometimes wonder whether it is always the left shoulder, the right, or both. The answer is that it can be any of those. A systematic review examining referred shoulder pain across multiple intra-abdominal conditions found that the lateralization of shoulder pain varies by the underlying cause. In ectopic pregnancy, the presentation was described as variable, meaning the pain may appear on the left, the right, or bilaterally, depending on where the blood pools against the diaphragm.³

Most ectopic pregnancies are tubal, and the tube ruptures into the pelvis and lower abdomen. Blood flows along anatomical pathways, often tracking up the right paracolic gutter (the natural channel along the right side of the abdominal cavity), which means right shoulder pain is frequently reported. But if there is a large volume of blood or if the patient’s position shifts where the blood settles, left-sided or bilateral shoulder pain is entirely possible. For comparison, the same systematic review noted that left-sided shoulder pain was more reliably linked to splenic problems, while right-sided shoulder pain was more consistent with gallbladder-related pathology.³ The takeaway is that you should not dismiss the symptom because the pain is on the “wrong” side. Any new, unexplained shoulder tip pain in the setting of early pregnancy symptoms deserves urgent evaluation.

When It Appears in the Timeline

Shoulder pain is not an early symptom of ectopic pregnancy. It typically shows up only after the ectopic has ruptured and blood has accumulated in the abdomen in sufficient quantity to reach and irritate the diaphragm. This means it is a late warning sign, and by the time you feel it, you are dealing with a surgical emergency.

The timeline usually unfolds something like this: a woman notices a missed period or light irregular bleeding, possibly with some lower abdominal cramping on one side. If the ectopic pregnancy is not detected and it ruptures, the initial event is often sudden, severe lower abdominal pain, sometimes accompanied by fainting, lightheadedness, or a feeling of pressure in the rectum. Shoulder pain tends to develop minutes to hours after the rupture begins, as blood accumulates beneath the diaphragm. In the 1923 JAMA case, the patient’s shoulder pains followed a fainting episode, which itself reflected the acute blood loss and hemodynamic shock of a rupture.²

In some cases, a slow leak rather than a dramatic rupture can produce a more gradual accumulation of blood, and shoulder pain may develop over a day or two rather than appearing all at once. This slower presentation can be particularly dangerous because the patient may not recognize the urgency of the situation, attributing the shoulder ache to something benign while internal bleeding continues.

Other Symptoms That Tend to Come With It

Shoulder pain from a ruptured ectopic pregnancy almost never appears in complete isolation. By the time blood has reached the diaphragm, the woman is typically experiencing several other symptoms that point toward something serious going on in the pelvis and abdomen:

Sharp lower abdominal pain: often one-sided, sudden, and severe.
Vaginal bleeding: usually different from a normal period, often darker in color and lighter in flow, sometimes described as spotting.
Dizziness or fainting: reflecting blood loss and dropping blood pressure.
Pale, clammy skin: another sign of significant internal bleeding.
Rectal pressure: blood pooling in the pelvis can press on surrounding structures and cause a sensation of needing to have a bowel movement.
A missed or late period: many women with an ectopic pregnancy have a positive pregnancy test or a recent missed period, though some do not know they are pregnant.

The combination of shoulder tip pain with any of these symptoms is what makes the clinical picture distinctive. Shoulder pain alone would not point a clinician toward ectopic pregnancy, but shoulder pain plus pelvic pain and a missed period triggers immediate investigation. Ultrasound imaging can often identify free fluid in the abdomen, as seen in a case report where transvaginal ultrasound confirmed both an adnexal mass and free fluid in the abdominal cavity.⁴

Why This Symptom Gets Overlooked

Shoulder pain is not the first thing most people or even many clinicians associate with a gynecological emergency. When a woman walks into an emergency department or a physical therapy clinic complaining of shoulder pain, the natural first thought is musculoskeletal: a strain, tendinitis, a rotator cuff issue. Ectopic pregnancy is among a range of systemic conditions that can produce shoulder or upper extremity symptoms, alongside pneumonia, liver disease, kidney stones, and cardiac problems.⁵ The sheer number of possible causes means that referred pain from an abdominal source can get lost in the differential, particularly if the patient does not mention pelvic symptoms or does not realize she is pregnant.

There are a few specific scenarios where the risk of misdiagnosis is especially high. If a woman is not aware she is pregnant, she has no reason to connect shoulder pain to her reproductive system, and neither does the clinician if pregnancy is not on the radar. If she presents to a specialist like an orthopedist or a physical therapist rather than an emergency department, the evaluation may focus entirely on the shoulder joint without considering referred pain from an internal source. And if the ectopic has ruptured slowly rather than dramatically, the initial symptoms may be mild enough that the woman delays seeking care, attributing her discomfort to a workout injury or sleeping awkwardly.

For anyone working in a clinical setting, the screening principle is straightforward: when a woman of reproductive age presents with unexplained shoulder tip pain, particularly if it is not reproduced by shoulder movement or palpation, a pregnancy test and abdominal evaluation should be considered early in the workup rather than as an afterthought.

Other Conditions That Produce Similar Referred Pain

The diaphragm-to-shoulder referred pain pathway is not exclusive to ectopic pregnancy. Several other conditions irritate the underside of the diaphragm and produce a similar pattern. The systematic review on referred shoulder pain found that lateralization and presentation varied across different abdominal pathologies: splenic abscess and splenic injury from colonoscopy were associated with left-sided shoulder pain, cholelithiasis (gallstones) with right-sided pain, and conditions like diaphragmatic endometriosis and exercise-related transient abdominal pain with variable presentation, much like ectopic pregnancy.³

Some of these causes are far less urgent than a ruptured ectopic, while others are equally dangerous. Splenic rupture after trauma can cause rapid internal bleeding and left shoulder pain. A perforated gastric ulcer can spill stomach contents against the diaphragm. A subdiaphragmatic abscess from any cause can produce the same irritation. And post-surgical patients sometimes experience shoulder tip pain from residual carbon dioxide gas used to inflate the abdomen during laparoscopic procedures, though this pain is typically mild and self-limiting over a few days.

What distinguishes ectopic pregnancy from these other causes is the clinical context: the patient is a woman of reproductive age, often with a positive pregnancy test, vaginal bleeding, and unilateral pelvic pain. When those elements are present alongside shoulder tip pain, the diagnosis becomes highly suspicious for a ruptured ectopic even before imaging is completed.

How Treatment Addresses the Shoulder Pain

The shoulder pain itself does not require separate treatment because it is a symptom of the underlying problem, not an injury to the shoulder. Once the ruptured ectopic pregnancy is treated surgically, usually by removing the affected fallopian tube or the ectopic tissue through laparoscopic surgery, and the blood in the abdominal cavity is cleared, the diaphragmatic irritation resolves and the shoulder pain fades.

How quickly the shoulder pain disappears after surgery depends partly on how thoroughly blood is removed from the abdominal cavity during the procedure. Research on peritoneal lavage during gynecologic laparoscopic surgery found that washing the abdominal cavity during the procedure reduced postoperative pain in the first 36 hours and lowered patients’ need for painkillers in the first three days after surgery.⁶ While that study focused on elective gynecologic surgery rather than emergency ectopic cases specifically, the principle applies: removing irritating material from the peritoneal cavity reduces pain driven by peritoneal and diaphragmatic irritation.

Some women report lingering shoulder discomfort for a day or two after laparoscopic surgery for ectopic pregnancy, partly because the laparoscopic procedure itself uses gas to inflate the abdomen, and residual gas can cause its own mild shoulder tip irritation as it is gradually absorbed. This post-surgical shoulder pain is typically milder and shorter-lived than the pain caused by the ruptured ectopic itself.

When to Seek Emergency Care

If you are in early pregnancy, suspect you might be pregnant, or have recently had a positive pregnancy test and you develop sharp pain at the tip of your shoulder that is not related to any injury or physical activity, treat it as a potential emergency. This is especially true if you also have lower abdominal pain, vaginal bleeding, dizziness, or a feeling of faintness. Do not wait for the pain to worsen or for additional symptoms to appear before going to the hospital.

Certain factors raise the overall risk of ectopic pregnancy and should lower your threshold for seeking evaluation: a history of pelvic inflammatory disease, previous ectopic pregnancy, fallopian tube surgery, use of an intrauterine device, or conception through assisted reproductive techniques. But ectopic pregnancy can occur in anyone, including women with none of these risk factors. The presence of unexplained shoulder tip pain in the context of early pregnancy symptoms is the critical signal, regardless of your personal risk profile.

Emergency departments diagnose ectopic pregnancy using a combination of blood tests (measuring the pregnancy hormone hCG) and transvaginal ultrasound. If the hCG level is above a certain threshold and no pregnancy is visible in the uterus on ultrasound, ectopic pregnancy becomes the leading diagnosis, and free fluid in the abdomen on imaging strengthens the suspicion of rupture. Treatment depends on the clinical situation: an unruptured ectopic may be managed with medication (methotrexate), while a ruptured ectopic with active bleeding requires surgery, typically laparoscopic, to stop the hemorrhage.

Diaphragmatic Endometriosis and Cyclical Shoulder Pain

There is a related but distinct condition worth knowing about, particularly for women who experience recurring shoulder tip pain timed to their menstrual cycle. Diaphragmatic endometriosis occurs when endometrial tissue implants on the diaphragm and responds to hormonal changes each month, causing cyclical irritation of the phrenic nerve. The result is shoulder pain that flares with menstruation and subsides afterward. The systematic review on referred shoulder pain noted variable lateralization in diaphragmatic endometriosis, similar to what is seen with ectopic pregnancy.³

While diaphragmatic endometriosis is far less acutely dangerous than a ruptured ectopic pregnancy, it shares the same referred-pain mechanism and can be similarly confusing for clinicians unfamiliar with it. Women who experience monthly shoulder pain around their period that cannot be explained by activity or posture should mention the cyclical pattern to their gynecologist, as it may point to endometrial implants on or near the diaphragm. The distinction matters: ectopic pregnancy shoulder pain is a one-time emergency event, while diaphragmatic endometriosis shoulder pain is chronic and recurrent, and the two require entirely different management approaches.

1
PubMed Central. A rare case report of successful surgical treatment of diaphragmatic pregnancy after chemotherapy
2
JAMA. Sudden Acute Pain in the Shoulders Associated With Acute Pelvic Pain in Women: A Symptom of Ruptured Ectopic Pregnancy, Indicating Subphrenic Blood Extravasation (Subphrenic Hemoperitoneum)
3
Journal of the Canadian Association of Gastroenterology. THE CLINICAL UTILITY OF REFERRED SHOULDER PAIN FOR THE DIAGNOSIS OF INTRA-ABDOMINAL PROCESSES: A SYSTEMATIC REVIEW
4
PubMed Central. Unintended and ectopic pregnancy in woman with iud translocation with history of two times previous cesarean section and history of spontaneous abortion: Case report
5
Journal of Hand Therapy. Screening for medical problems in patients with upper extremity signs and symptoms
6
PubMed. The role of peritoneal lavage in benign gynecologic laparoscopic surgery