Feeling weak and shaky with chest pain can come from low blood sugar, a panic attack, dehydration or too much caffeine, but it can also signal a heart attack, a dangerous heart rhythm or very low blood pressure. If weakness and chest pain come on suddenly, last more than a few minutes, or come with sweating, breathlessness or fainting, call 911.
Medically reviewed by
Board-certified cardiologist · Katy & Sugar Land, TX
Fellowship-trained in cardiovascular disease, interventional cardiology, echocardiography and advanced heart failure and transplant cardiology. Former Assistant Professor of Cardiology at McGovern Medical School.
Why do I feel weak and shaky with chest pain?
Weakness and shakiness are signs that the body is under stress or not getting enough blood flow, oxygen or fuel. When they show up together with chest pain, doctors think about two broad groups of causes: problems that reduce blood flow from the heart, and problems that set off the body’s adrenaline (fight-or-flight) response.
| Possible cause | Other clues | Urgency |
|---|---|---|
| Heart attack | Chest pressure, cold sweat, nausea, breathlessness, sudden weakness or fatigue | Emergency: call 911 |
| Abnormal heart rhythm | Racing, pounding, very slow or irregular heartbeat; dizziness or fainting | 911 if fainting or ongoing |
| Low blood sugar (hypoglycemia) | Shaking, sweating, hunger, confusion; often in people taking diabetes medicines | Treat right away; 911 if confused or unresponsive |
| Panic attack | Sudden fear, racing heart, tingling, fast breathing; peaks within minutes | See a doctor; heart causes ruled out first |
| Dehydration or heat illness | Thirst, dark urine, dizziness on standing, recent heat exposure | 911 if confused or fainting |
| Low blood pressure | Lightheaded on standing, blurred vision, fatigue | See a doctor; urgent if fainting |
| Anemia | Gradual fatigue, pale skin, breathlessness with activity | See a doctor soon |
| Too much caffeine, stimulants or an overactive thyroid | Jittery, fast heartbeat, trouble sleeping | See a doctor if persistent |
Weakness and chest pain as heart attack symptoms
Not every heart attack causes crushing chest pain. Some people, especially women, older adults and people with diabetes, mainly feel sudden weakness, unusual fatigue, shakiness, cold sweats, nausea or shortness of breath with only mild chest discomfort. The National Heart, Lung, and Blood Institute notes that heart attack symptoms can differ between people and from one episode to another. Learn more about heart attack symptoms in women.
- Chest pressure or pain lasting more than a few minutes
- Cold sweat, nausea or shortness of breath
- Fainting or nearly fainting, or a very fast, slow or irregular heartbeat
- Confusion, trouble speaking, or weakness on one side of the body
- Symptoms that do not improve after treating low blood sugar
Heart rhythm problems and low blood pressure
A heart that beats too fast, too slow or irregularly may not pump enough blood to the brain and muscles. The result can be weakness, shakiness, lightheadedness and chest discomfort. Common examples include atrial fibrillation, supraventricular tachycardia (SVT) and bradycardia.
Rhythm problems often come and go, so a normal EKG at the doctor’s office does not rule them out. A Holter monitor or event monitor can capture the rhythm during symptoms. If you feel faint when you stand up, low blood pressure may be part of the picture.
Low blood sugar, shakiness and chest discomfort
Low blood sugar triggers a rush of adrenaline that causes shaking, sweating, a pounding heartbeat, anxiety and sometimes chest discomfort. It is most common in people taking insulin or certain diabetes pills, especially after skipping a meal or exercising more than usual. The NIDDK recommends checking blood sugar and treating a low reading with fast-acting carbohydrate.
Diabetes also raises heart disease risk and can blunt chest pain, so people with diabetes should not assume shakiness is “just low sugar” if symptoms do not improve quickly once sugar is corrected. Learn about diabetes and heart disease.
Anxiety, panic attacks and dehydration
Panic attacks cause a sudden surge of fear with chest pain, trembling, a racing heart, breathlessness and tingling. They usually peak within about ten minutes. They are real and treatable, but because they mimic heart problems, a first episode should be evaluated. See can anxiety cause chest pain and palpitations?
Dehydration and heat illness are common in Houston’s hot, humid months. Losing fluid lowers blood pressure and raises heart rate, which can cause weakness, shakiness, dizziness and chest discomfort. Read can dehydration cause chest pain and dizziness?
How doctors find the cause
Evaluation usually includes your history and vital signs, an EKG, blood tests (blood count, blood sugar, electrolytes, thyroid and sometimes troponin), and depending on findings, an echocardiogram, heart rhythm monitoring or a stress test. Bring a record of when symptoms happen, what you were doing, and any home blood pressure, pulse or blood sugar readings.
What to do when you feel weak, shaky and have chest pain
- Stop and sit or lie down so you do not fall.
- If you have diabetes and a meter, check your blood sugar and treat a low reading as your doctor has advised.
- If symptoms are severe, last more than a few minutes, or come with any warning sign below, call 911.
- If symptoms pass quickly and fully, arrange a doctor visit within a few days and note what happened.
Cardiology care in Katy and Sugar Land
If episodes of weakness, shakiness and chest discomfort keep coming back, Advanced Cardiology can look for heart rhythm, blood pressure and blood flow causes. Dr. Khalid sees patients at our Katy and Sugar Land offices, where EKG and echocardiogram testing are available and heart monitors can be started. See also our pages on dizziness and fainting and chest pain care.
Katy office: 410 W Grand Pkwy S, Suite 4D, Katy, TX 77494
Sugar Land office: 7102 Tarrington Ave, Suite 505, Sugar Land, TX 77479
Phone: (713) 258-6111
We also see patients from Fulshear, Richmond, Rosenberg, Stafford, Missouri City and west Houston.
Recurring weak, shaky spells with chest pain?
A heart monitor and a focused cardiology exam can often find the cause. Request a visit in Katy or Sugar Land.
Having symptoms right now? Call 911. Do not wait for an appointment.
Frequently asked questions
Why do I feel weak and shaky with chest pain?
Common causes include low blood sugar, panic attacks, dehydration, too much caffeine and low blood pressure. More serious causes include a heart attack and abnormal heart rhythms. Sudden or severe symptoms need 911.
Can a heart attack make you feel weak and shaky?
Yes. Sudden weakness, unusual fatigue, cold sweats and shakiness can be heart attack symptoms, sometimes with only mild chest discomfort. This is more common in women, older adults and people with diabetes.
Can low blood sugar cause chest pain?
Low blood sugar releases adrenaline, which can cause a pounding heartbeat, shaking, sweating and chest discomfort. If chest pain continues after blood sugar is corrected, seek emergency care.
Can anxiety cause weakness, shaking and chest pain?
Yes. Panic attacks can cause trembling, weakness, a racing heart and chest pain. Because these symptoms overlap with heart problems, a first episode should be checked before it is attributed to anxiety.
Can dehydration make your chest hurt and make you shaky?
Dehydration can lower blood pressure and raise heart rate, causing weakness, shakiness, dizziness and chest discomfort, especially in hot weather. Severe symptoms or fainting need emergency care.
What tests check for heart causes of weakness and chest pain?
Doctors often start with an EKG and blood tests. Depending on results, an echocardiogram, heart rhythm monitor or stress test may follow.
When should I see a cardiologist for weakness and chest pain?
See a cardiologist if episodes keep returning, happen with exertion or palpitations, or you have heart risk factors such as high blood pressure, diabetes or high cholesterol.
Trusted health resources
- Heart Attack: Symptoms, National Heart, Lung, and Blood Institute (NIH)
- Low Blood Glucose (Hypoglycemia), National Institute of Diabetes and Digestive and Kidney Diseases (NIH)
- Panic Disorder, MedlinePlus, U.S. National Library of Medicine
- Dehydration, MedlinePlus, U.S. National Library of Medicine
- Anemia, MedlinePlus, U.S. National Library of Medicine
Medical disclaimer: This article is for general education and is not a diagnosis or a substitute for care from your own doctor. If you think you may be having a heart attack, stroke or another emergency, call 911 right away.
