Phrenic nerve


The phrenic nerve is a bilateral nerve that is composed of the cervical nerves C3, C4 and C5. It guides both sensitive fibers for the pericardium (Pericardium), the lung membrane (Pleura) and the peritoneum (peritoneum), as well as motor parts that supply the diaphragm. Due to its function, the phrenic nerve likes to hiccup (Singultus) and breathing difficulties that can occur with paralysis of the diaphragm.

Nerve course

After that the cervical nerves are located on the right as well as on the left side C3, C4 and C5 have joined together to form the phrenic nerve, this runs along the Scalenus anterior muscle, a lateral neck muscle, down. The course of the phrenic nerve is lateral to the Vagus nerve. The phrenic nerve then runs between the vena and the subclavian artery into the thoracic area.

The further course is laterally along the Mediastinum, a body cavity delimited by connective tissue plates, which lies between the two lungs, downwards in the direction diaphragm. It is important that the phrenic nerve bellyward to the to lung pulling blood vessels and bronchi. Once at the diaphragm, the left phrenic nerve passes this along with the esophagus and the right one with the lower one Vena cava.

After the nerve has supplied the diaphragm with motor and sensory fibers, it gives off other sensitive branches, the so-called Rami phrenicoabdominales, for innervation of the peritoneum in the upper abdomen and ends then in its course. On its way, the phrenic nerve regularly gives further sensitive nerve branches for the nervous supply of the Heart sac and des Pulmonary membrane from.


One cause that can lead to irritation of the phrenic nerve is a increased pressure in the abdomen, which also relates to the diaphragm affects. This can be done with a Laparoscopy with keyhole technology or through one's own fault rapid and lush Ingestion or the like occur.
Behind an injury to the phrenic nerve associated with a Paralysis of the diaphragm can go hand in hand, on the one hand, direct damage to the nerve can come from, for example, a surgical intervention in the chest in which the nerve is damaged or severed.

On the other hand, the phrenic nerve can lose its function due to inflammation. Here would be Guillain-Barré Syndrome, multiple sclerosis and pathogens like Borrelia, to mention. In the case of inflammation, the symptoms can be reduced by treating the cause. However, a 100% restoration of the original state cannot always be guaranteed.

Symptoms of complaints

Symptoms that can occur as a result of irritation of the phrenic nerve include the hiccupwhich in most cases can be regarded as harmless, but sometimes can also acquire a pathological value. The sudden contraction of the Diaphragm hiccups can lead to pain, especially if they last for a long time, and the person affected can find it extremely uncomfortable. You can also choke on yourself.

Other symptoms that can be traced back to the phrenic nerve are breathing difficulties, caused by a partial or complete paralysis of the diaphragm. Especially that breathe in is made more difficult because the contraction of the diaphragm supports exactly this process and the lung Creates space to unfold. Even when lying down, the abdominal organs can now exert more pressure on the lungs when the diaphragm is paralyzed and Shortness of breath cause. Those affected feel very short of breath, which is made worse by exertion.

Since the phrenic nerve also carries sensory fibers, pain in the supplied structures, such as the Heart sac, of Pulmonary membrane or des Peritoneum come when they are inflamed, for example, or increased pressure irritates the nerve.

Irritation of the phrenic nerve

Phrenic nerve irritation is often caused by increased pressure in the abdomen, which is applied to the diaphragm acts, triggered. This can be done, for example, after a Laparoscopy, in which the examination instruments are inserted into the abdomen using keyhole technology and the abdomen is inflated with gas for better visibility. But hasty consumption of a large meal can also lead to the symptoms. The result of irritation of the phrenic nerve is usually the hiccup.


Of the hiccup is caused by the sudden, knee-jerk and involuntary contraction of the Diaphragmwhich leads to inhalation and the abrupt end of the Vocal foldsthat ends the process. Usually the hiccups occur several times in a row and can therefore last for a certain time.
An irritation of the phrenic nerve, which supplies the diaphragm with motor, is suspected to be the cause. The temporary irritation is classified as harmless. Chronic irritation caused by illness, on the other hand, has to be clarified and can lead to serious complications.

Hiccups due to temporary irritation can be caused, for example, by increased stretching of the Stomach after ingestion or by eating spicy food. Excitement or loud laughter can also cause hiccups, as this can irritate the phrenic nerve. If the nerve is irritated by a pathological process, such as an inflammation in the abdomen or the stomach and esophagus, the hiccups can be chronic. Chronic hiccups are often associated with pain and distress for the person concerned.

Damage to the phrenic nerve

The damage to the Phrenic nerve can have various causes and lead to the loss of its function. Consequently, it can lead to unilateral damage to the nerve Elevation of the diaphragm come on the affected side. This is usually the case with damage to the phrenic nerve on both sides entire diaphragm affected by paralysis. The damage can already occur in the Spinal cord or in the corresponding nerve roots when exiting the Spinal canal respectively. On the one hand, the phrenic nerve can be damaged directly, for example by a cutting cut in the course of an operation in the chest or neck, or for example by a tear caused by an accident injury.

Furthermore, a tumor or the like can press on the nerves and thereby permanently affect them. Also a Herniated disc of the cervical spine or a similar space-consuming process in the area of Cervical spine can cause damage to the phrenic nerve. The likelihood that the phrenic nerve will recover by itself after an impairment always depends on the extent of the injury. With a complete separation, however, there is a growing together and regaining of the function rather unlikely.

Inflammation of the phrenic nerve

Inflammation of the phrenic nerve can lead to flaccid paralysis of Diaphragm especially if the nerve is affected on both sides. The nerve roots that form the phrenic nerve can, for example, from the so-called Guillain-Barré Syndrome be affected, which leads to an acute inflammation, or in the context of a Lyme disease changed inflammatory.

Paresis of the phrenic nerve

Paresis, i.e. paralysis, of the phrenic nerve can occur either on one side or on both sides, depending on the underlying cause. Since the diaphragmatic muscle is also supplied with motor from the phrenic nerve and, thanks to this, can contract for inhalation, this function is partially or even completely deactivated in the event of nerve damage.

In unilateral paresis, the Elevation of the diaphragm Thus, only observing on the affected side causes breathing problems. With special Breathing exercises as part of a physical therapy the problem of inhalation can be addressed by a phrenic nerve paresis and lead to an improvement. However, the phrenic nerve is bilateral in front The supply of the diaphragm is damaged and fails, so it can lead to a complete paresis of the diaphragm, i.e. an inability to contract when inhaling, around the lung To make room, and the associated life-threatening breathing problems.

In the case of diaphragmatic palsy, the abdominal organs can also move upwards, especially when lying down heart and lung press, which exacerbates the problem. The phrenic nerve can be damaged in its course from the neck to the diaphragm, either through an injury or the compression of the nerve by, for example, a tumor. In addition, that Spinal cord itself or the nerve roots of the cervical nerves three to five are damaged in such a way that the phrenic nerve loses its function. Again, an accident with injury to the Cervical spine, a process of wear and tear in the spine or a tumor behind it.

Diagnosis of problems with the phrenic nerve

To diagnose phrenic nerve paresis, one can have one X-ray of the chest, in which the Elevation of the diaphragm is easy to judge. In addition, during the physical examination one can see the increased activity of the Auxiliary respiratory muscles recognize between the ribs.
In theory, you can also use Electroneurography and Electromyography test the function of the phrenic nerve, but it is difficult to do in practice. If inflammation is suspected, the diagnosis can be extended to a corresponding examination of blood and nerve fluid in order to confirm the suspicion.
To clarify one Herniated disc of the cervical spine can a MRI of the cervical spine be made.

Therapy options for complaints

If there is a paresis of the phrenic nerve, certain respiratory problems can be used as a therapy Breathing exercises be made, in worse cases is one artificial respiration necessary.
If there is an inflammatory process behind the paresis, therapy of the inflammation, for example with antibiotics, antivirals, Cortisone or a plasma separation.
If an irritation of the phrenic nerve is in the foreground, the symptoms disappear like hiccup, often by itself and can sometimes be assisted by relaxation exercises.

Prognosis in case of complaints

Depending on the cause of the paresis or irritation of the phrenic nerve, the symptoms can decrease or persist permanently.

Prophylactic behavior for prevention

In order to counteract irritation of the phrenic nerve from eating too quickly, you can first try to eat more slowly. Prophylaxis is required for the remaining damage to the phrenic nerve difficult to be implemented, since the consequences cannot always be determined in advance, for example during an operation. In order to counter breathing difficulties with prophylaxis after damage, it is recommended in some cases through special physical therapy to train the remaining auxiliary respiratory muscles.