14 Major Symptoms of Thoracic Outlet Syndrome

2. Numbness in the Fingers

You may feel numbness in your fingers if you have thoracic outlet syndrome, often affecting your pinky and ring fingers first. The numb feeling can spread along the inner side of your forearm. Squeezed nerves near your collarbone cause this numbness, as they travel from your neck down into your arm and hand.

When pressure builds in this tight space, the signals to your fingers do not move as they should. You might notice a “pins and needles” feeling, and your fingers may feel less sensitive to touch, heat, or cold. At times, the numbness may come and go. Certain arm positions, such as lifting your arms or carrying heavy bags, can make it worse.

You may also notice symptoms at night, especially if you sleep with your arms raised. Numbness can affect your grip, which can make you drop objects or struggle with small tasks like buttoning a shirt. If the pressure continues, the muscles in your hand can weaken over time.

3. Weak Grip

You may notice that your grip feels weaker than usual, which makes it difficult to open jars, hold a coffee mug, or carry grocery bags. Objects can slip from your hand even when they are not heavy. When nerves in the thoracic outlet get pressed, they cannot send strong signals to your hand and forearm muscles.

This can make your arm feel tired after simple tasks, and writing, typing, or using tools may become harder over time. The weakness may affect one hand more than the other, usually on the side with symptoms. You might see mild muscle shrinkage at the base of your thumb, and numbness or tingling may accompany the weak grip.

Certain arm positions, like reaching overhead or lifting your arms for a long time, can worsen the weakness. When you lower your arm and rest, your strength may improve slightly, but the problem can return with activity.

4. Weak Muscles

Your arm may feel weak or tired much faster than usual, often affecting one side more. Tasks like lifting a bag or brushing your hair can feel harder than they should. Thoracic outlet syndrome presses on the nerves that control your shoulder, arm, and hand muscles, which prevents them from sending strong signals.

Over time, this can reduce your muscle strength and control. You might struggle with grip strength, find objects slipping from your hand, or have trouble opening jars or holding tools. Some people also notice less muscle tone in the hand, especially at the base of the thumb.

Weakness often appears along with symptoms like tingling, arm fatigue with light activity, pain in the neck, shoulder, or arm, and a cold or pale hand. Certain arm positions, such as raising your arm overhead or reaching forward for a long time, can increase pressure in the narrow space between your collarbone and first rib.

5. Headaches

You may notice headaches along with pain in your neck and shoulder. Thoracic outlet syndrome irritates nerves and tightens muscles at the base of your neck, which causes tension that spreads upward and triggers head pain. These headaches often start in the back of your head and can move toward your temples or forehead, usually feeling like a dull ache or steady pressure.

Arm or shoulder positions such as lifting your arms, carrying heavy bags, or working at a desk with poor posture can worsen the headache. Tight neck muscles and reduced blood flow from compressed vessels both contribute. When blood vessels are involved, your arm may feel cold, tired, or swollen on the same side as the headache. Headaches linked to thoracic outlet syndrome may come and go, lasting for hours or happening after repeated arm movements.

6. Swollen Shoulders, Neck, and Hands

You may notice swelling in your shoulder, neck, arm, or hand on one side of your body. Compressed blood vessels in the thoracic outlet can disrupt blood flow, and this causes fluid buildup in the tissues. Your hand or arm may look larger than usual, and rings, watches, or sleeves may suddenly feel tight. The skin can also look slightly blue or pale and may feel cold to the touch.

Swelling often appears with other symptoms such as heaviness, aching, or tightness in the area. Some people notice that their arm gets tired quickly, especially after lifting or carrying objects. Symptoms may worsen when you raise your arms or carry something heavy. Swelling tied to thoracic outlet syndrome usually affects only one side and may fluctuate throughout the day depending on posture and activity levels.

7. Fatigue in Arms

Your arm may feel tired very quickly, even during simple tasks. Activities like brushing your hair, carrying groceries, or typing can make your arm feel weak, often affecting one arm more than the other. Thoracic outlet syndrome compresses nerves or blood vessels near the top of your ribs, so your muscles may not get enough steady blood flow or clear nerve signals.

As a result, your arm can feel heavy, drained, or slow to respond. Your arm may tire faster when you lift it above shoulder level, such as when holding your phone or reaching into a cabinet. The tired feeling may improve when you lower your arm and rest.

Arm fatigue can also appear with symptoms like pins and needles, mild swelling, aching in the shoulder or neck, and a cold feeling in the hand. Repeated fatigue can limit how long you use your arm without discomfort, and you may start avoiding certain movements because they bring on weakness or strain.

8. Blood Clot in the Veins in the Upper Part of the Body

Thoracic outlet syndrome can press on the veins near your collarbone and upper ribs, which slows blood flow and allows a clot to form in the veins of your upper body, often in your arm. You may notice sudden swelling in one arm, which can feel heavy, tight, or painful.

The skin may look red or bluish and feel warm to the touch. These clots often develop in the deep veins of the arm. If part of the clot breaks off, it can travel to your lungs and block blood flow, which can cause sudden shortness of breath, sharp chest pain when you breathe in, or coughing up blood.

Treatment typically involves anticoagulant medications to help prevent the clot from growing and to reduce the risk of new clots forming. In some cases, you may need other procedures to remove the clot or relieve pressure in the area.

9. Poor Posture

Poor posture plays a clear role in thoracic outlet syndrome. When you slump your shoulders or push your head forward, you narrow the space between your collarbone and first rib, pressing on nerves and blood vessels that travel to your arm.

You may notice symptoms after long hours at a desk or while using a phone. Sitting with rounded shoulders and a bent neck places steady pressure on the upper chest area, which leads to tingling, numbness, or aching in one arm.

Poor posture affects more than just your back, as it changes how your neck and shoulder muscles work. Tight chest muscles and weak upper back muscles can pull your shoulders out of alignment. You might also feel your arm tire easily, and some people notice coldness, mild swelling, or color changes in the hand when posture stays poor for long periods.

10. Loss of Mobility

Loss of mobility develops when nerves or blood vessels in your upper chest become compressed, which limits how well your shoulder, arm, and hand move. You may notice stiffness or a reduced range of motion during daily tasks.

Simple actions such as brushing your hair, fastening a seatbelt, or carrying groceries may feel harder, and your arm can feel tight, weak, or heavy after only a short period of use. In some cases, swelling or pain adds to the restriction. If blood flow decreases, your arm may feel cold or tired more quickly.

If nerves become affected, you may also notice numbness or tingling along with limited movement. Repetitive overhead work, poor posture, or past injuries can make these limits more noticeable. Over time, reduced flexibility and muscle imbalance around the shoulder and upper ribs may further decrease movement and make routine activities more challenging.

11. Neurogenic Thoracic Outlet Syndrome

Neurogenic thoracic outlet syndrome occurs when nerves near the top of your ribs get pressed or squeezed as they travel from your neck into your shoulder, arm, and hand. When pressure builds in this space, you may notice changes in how your arm feels or works. This is the most common type of thoracic outlet syndrome and usually affects one arm.

Your symptoms may get worse when you lift your arm, carry heavy items, or keep your arms raised for long periods. Common symptoms include numbness or tingling in your fingers and a weak grip. They may also include pain in your neck, shoulder, or arm, burning or aching that spreads down your arm, and muscle loss at the base of your thumb in severe cases.

Your arm may also feel tired quickly, even during simple tasks like brushing your hair or typing. Some people drop objects because their hands feel weak. Poor posture, repetitive arm movements, heavy lifting, or a past neck or chest injury can raise your risk. Treatment often includes physical therapy to improve posture and strengthen shoulder muscles.

12. Increased Heart Rate and High Blood Pressure

Thoracic outlet syndrome can affect more than your arm and shoulder. When blood vessels near your upper ribs get compressed, your body may respond by raising your heart rate and blood pressure. You may notice that your heart beats faster than normal, even when you are resting, and this can feel like pounding, fluttering, or a strong pulse in your chest or neck.

These changes happen because narrowed blood vessels make it harder for blood to flow smoothly, so your body increases pressure inside the arteries. Over time, this can lead to higher blood pressure readings. You might not feel symptoms right away, but some people report headaches, lightheadedness, or a sense of pressure in the head.

If a blood vessel becomes significantly compressed, your body works harder to push blood through the tight space. This extra effort can strain your heart. In rare cases, a blood clot can form in the affected arm, which may also affect circulation and heart function.

13. Discoloration

You may notice changes in the color of your hand or arm when you have thoracic outlet syndrome. When a blood vessel gets compressed and limits normal blood flow, your skin may not get enough oxygen.

Your hand or fingers might look pale, bluish, or even gray, and on darker skin tones, the area may appear darker than usual or have a dull tone. You might see them when you raise your arm, carry something heavy, or hold your arm in one position for a long time.

Cold temperatures can also make the color change more noticeable. In some cases, your arm may also feel cold to the touch, and you may notice swelling along with the color shift. These signs suggest that a vein or artery is under pressure. If a blood clot forms, the arm may become red or purple and feel warm and painful, requiring immediate emergency care.

14. Throbbing Lumps

You may notice a throbbing lump near your collarbone or at the base of your neck when a blood vessel in the thoracic outlet gets squeezed. The pressure causes the vein or artery to swell, which may feel like a soft or firm bump. The lump may pulse in time with your heartbeat.

You might also see swelling in your arm or hand on the same side, and the area can feel tender or warm. In certain cases, the skin over the area looks pale, blue, or slightly red. Your arm can feel heavy or tight, which points to reduced blood flow or a blocked vein.

A painful, throbbing lump with redness and warmth may signal a blood clot. You may also feel cramping or deep aching in your arm. These lumps often appear with other symptoms such as arm fatigue, numbness, or tingling. When you raise your arm or carry something heavy, the swelling or throbbing can become more noticeable.