Vomiting: Causes, Complications, Pathophysiology, Treatment

Article by Dr Raghuram Y.S. MD (Ay)
Vomiting is a disturbing condition which all of us would have experienced at one or the other point of our life. It might be due to incompatible foods that we have consumed in terms of quality or quantity or as an effect of some chronic illness or toxins which are incompatible with our body or due to normal body behaviour as in pregnancy. 

Vomiting might be a simple one, occurring once or twice, which often settles by itself. Some types of vomiting, especially those which are secondary to some systemic diseases are stubborn, recurring and are life threatening, since they too like diarrhoea cause severe dehydration and pressure on heart and brain.

What is Vomiting?

Vomiting is the forcible ‘voluntary’ or ‘involuntary’ emptying (throwing up) of stomach contents through the mouth and sometimes through nose. Many times, vomiting is preceded by nausea. Nausea is an uneasiness of the stomach that often comes before vomiting. This causes a feel to vomit and many times may cause vomiting or severe uneasiness in the form of chest and abdominal discomfort, headache, restlessness, nervousness etc.

Vomiting and Nausea are not diseases but are symptoms of many other pre-existing conditions.
Anti-emetics or medicines which check vomiting may be needed to suppress nausea and vomiting. In severe cases, intravenous fluids may be required, especially when dehydration develops.

‘Regurgitation’ – Vomiting is different from another condition called regurgitation. Regurgitation is the return of undigested food, back up the food pipe (oesophagus) to the mouth. This will not be associated with force, nausea or displeasure associated with vomiting. The causes also differ.

Other names – Vomit, Emesis, Heaving, Puke, Throwing up
Read related: 21 Lifestyle And Prevention Tips To Stop Vomiting And Nausea

Causes

Causes (Differential diagnosis of Vomiting) –
Vomiting can be caused by many conditions. It might occur as a response to gastritis or poisoning or as a sequel of disorders like brain tumours, raised intracranial pressure etc.
Below mentioned are the different conditions which cause vomiting or are associated with vomiting.

Causes in gastro-intestinal (digestive) tract –

• Gastritis – inflammation of the stomach wall
• Gastro-enteritis – inflammation of the stomach and small bowel (small intestine) wall
• Gastro-oesophageal Reflux Disease – also called acid reflux where in stomach contents come back up into the food pipe resulting in symptoms like heartburn, bad breath, chest pain, vomiting etc
• Bowel obstruction – obstruction in small or large bowel
• Pyloric stenosis – typically causes forceful vomiting (Pylorus is the end part of the stomach where it opens into small bowel, obstruction here is called pyloric stenosis)
• Over eating – excess eating also puts pressure on the stomach leading to vomiting
• Acute abdominal pain
• Peritonitis – inflammation of the covering layers of the abdominal viscera (peritoneum)
• Ileus – painful obstruction of ileum (last part of small intestine / bowel) or other part of small intestine
• Food allergies – in conjunction with hives or swelling
• Cholecystitis – inflammation of gall bladder
• Pancreatitis – inflammation of pancreas
• Appendicitis – inflammation of appendix
• Hepatitis – inflammation of liver tissue
• Food poisoning – any incompatible food can be a food poison
• Lactose intolerance or milk allergy – caused in children due to allergic reaction to cow’s milk proteins

Conditions related to Brain and sensory system

• Motion sickness – caused by overstimulation of labyrinthine canals of the ear
• Meniere’s disease – is a disorder of the inner ear that causes severe dizziness (vertigo), ringing in the ears (tinnitus), hearing loss and feeling of fullness or congestion in the ear.
• Concussion – brain injury caused by a blow to the head or a violent shaking of the head and body
• Cerebral haemorrhage – internal bleeding in the brain
• Migraine – Headache of varying intensity, accompanied by nausea and sensitivity to light and sound
• Benign intracranial hypertension – or Idiopathic intracranial hypertension or pseudo-tumour cerebri (PTC), is a neurological disorder that is characterized by increased intracranial pressure (pressure around the brain) in the absence of tumour or other diseases.
• Hydrocephalus – build up of fluid in the cavities deep within the brain
• Brain tumours

Metabolic disturbances (cause irritation both in the stomach and other parts of the brain and cause vomiting) –

• Hypercalcaemia – high calcium levels in the blood
• Uraemia – high accumulation of urea in the blood, usually due to renal failure
• Adrenal insufficiency – disorder in which the adrenal glands (glands located over the kidneys) do not produce sufficient quantities of important hormones
• Hypoglycaemia – low blood sugar
• Hyperglycaemia – high blood sugar or glucose in blood stream, often associated with diabetes mellitus

Pregnancy –
Hyperemesis (excessive vomiting) and morning sickness are common in pregnancy

Drug reactions (vomiting may occur as an acute somatic response to)

• Alcohol, Opioids
• Selective serotonin re-uptake inhibitors
• Chemotherapy drugs
• Enthenogens (peyote or ayahuasca)

Stomach flu (illness that refers to gastric inflammation caused by a range of viruses and bacteria) –
– Noro-virus (Norwalk virus or Norwalk agent)
– Swine influenza

Emetics –
Emetics are substances that induce vomiting when administered orally or by injection. It is used when any incompatible or harmful substance has been taken and must be expelled from the body immediately. This removes the substance before it is absorbed into the body.
Example, syrup of ipecac, salt water and mustard, copper sulphate, hydrogen peroxide (veterinary) etc.

Social cues –
Nausea or vomiting is caused when someone else vomits in our close proximity, due to the sight or smell of vomit. This has been commonly found among primates, in drinking parties, intense vomiting in ayahuasca ceremonies (considered as spiritual cleansing), mass hysteria (fears of vomiting or want to vomit by seeing someone do it) etc
Read related: 21 Lifestyle And Prevention Tips To Stop Vomiting And Nausea

Miscellaneous causes of vomiting –

• Self induced vomiting as in – Eating disorders (Anorexia nervosa or Bulimia nervosa), Induced to eliminate ingested poison, People engaged in binge drinking induce vomiting to make room in their stomachs for more alcohol, People suffering from nausea may induce vomiting in hopes of feeling better etc
• Post operative nausea and vomiting – occurs after surgery
• Disagreeable sights or disgust – smells or thoughts of decayed matter, other’s vomit, thinking of vomiting etc
• Extreme pain – like intense headache or myocardial infarction (heart attack)
• Cyclic vomiting syndrome – poorly understood condition with attacks of vomiting
• Ionizing radiation – high doses cause vomit reflex
• Violent episodes of – cough, hiccups or asthma
• Rumination syndrome – under-diagnosed and poorly understood disorder that causes sufferers to regurgitate food shortly after ingestion
• Anxiety
• Depression
• Over-exertion
• Violent emotions

Complications

Aspiration – when the gastric contents enter the respiratory tract, it really gets lethal. It is generally protected from gag or cough reflex, but not in those who consume alcohol or on anaesthesia. Aspiration causes choking and aspiration pneumonia

Dehydration and electrolyte imbalance – depletion of water stores occurs due to prolonged or excessive vomiting. This will alter the electrolyte status. Gastric vomiting leads to loss of acid (protons) and chloride, hypochloremic metabolic alkalosis and hypokalemia (potassium loss). Since the person is not able to take food, he may become cachectic. Metabolic acidosis occurs due to vomiting of intestinal contents including bile acids and HCO3.

Mallory Weiss tear – erosions or small tears occurring in the oesophageal mucosa caused by repeated or profuse vomiting are called Mallory-Weiss tear. It occurs if fresh red blood is mixed with vomit after several episodes.

Dentistry – destruction of tooth enamel occurs due to recurrent vomiting (due to acidity of the vomit), in cases like bulimia nervosa. Digestive enzymes degrade the tissue of the gums.
Read related: 25 Easy, Effective Home Remedies for Vomiting And Nausea

Pathophysiology

Patho-physiology of Vomiting –
Receptors represeinting a ‘chemoreceptor trigger zone’ known as ‘area postrema’ are located on the floor of the 4^th ventricle of the brain. The stimulation of this area can lead to vomiting.

Various pathways of vomiting –

• The ‘chemoreceptor trigger zone’ has numerous dopamine D₂ receptors, serotonin 5-HT₃ receptors, opioid receptors, acetylcholine receptors and receptors for substance P. stimulation of different receptors are involved in different pathways leading to emesis. In the final common pathway, substance P appears involved.
• The vestibular system which sends information to the brain via vestibulocochlear nerve (VII cranial nerve) takes part in causing motion sickness
• The Vagus nerve (X cranial nerve) gets activated when the pharynx is irritated. This leads to gag reflex.
• The vagal and enteric nervous system inputs transmit information regarding the state of GI system. Irritation of GI mucosa by chemotherapy, radiation, distension or acute infections (gastroenteritis) activates 5-HT₃ receptors
• The CNS mediates vomiting that arises from psychiatric disorders and stress from higher brain centers

The act of vomiting encompasses 3 outputs initiated by the ‘chemoreceptor trigger zone’, They are –

– Motor
– Parasympathetic nervous system (PNS)
– Sympathetic nervous system (SNS)

They are as follows:

• Increased salivation (to protect tooth enamel from stomach acids) – part of PNS output
• Deep breath – to avoid aspirating vomit
• Retro-peristalsis – sweeps up the digestive contents from the middle part of small intestine, through the pyloric sphincter into the stomach
• Lowering of Intra-thoracic pressure – with increased abdominal pressure, propels stomach contents into the oesophagus.
• Retching – preceding vomiting
• SNS response – initiated by vomiting, causing sweating and increased heart rate

Vomiting phases

Retching phase – In this, few coordinated contractions take place in the abdominal muscles along with diaphragm and muscles of respiratory inspiration. Nothing is expelled.

Expulsive phase – follows the retching phase. Enormous shifts in both diaphragm and abdomen brings about intense pressure in the stomach. These shifts are nothing but vigorous contractions of these muscles that last for a prolonged time. When the upper oesophageal sphincter relaxes, the pressure is suddenly released, resulting in expulsion of gastric contents. The relief of pressure and release of endorphins into the bloodstream after the expulsion causes relief from vomiting.
Read related: Chardi Roga – Vomiting: Ayurveda Explanation, Types, Symptoms

Contents of Vomitus

Vomiting generally consists of contents of stomach. Gastric secretions and vomit are highly acidic. In gastric vomiting, we can see the recently taken food.

Fresh blood in vomit is called haematemesis (blood vomiting). The blood has a coffee ground appearance. In severe vomiting, bile can enter the vomit due to duodenal contractions. Fecal vomiting is associated with intestinal obstruction or a gastro-colic fistula.

Dry heaves (non-productive emesis) – vomiting reflex continuing for an extended period with no appreciable vomitus

Colour of vomit

Bright red vomit – suggests bleeding from food pipe (oesophagus)
Dark red vomit with liver like clots – points towards profuse bleeding in the stomach (perforated ulcer)
Coffee ground like vomit – suggests less severe bleeding in the stomach
Yellow vomit – suggests bile

Epidemiology

Nausea and / or vomiting are the main complaints in 1.6% of visits to family physicians in Australia

Is vomiting harmful?
Usually vomiting is harmless, but can be a sign of a more serious illness. Serious conditions that may result in nausea or vomiting are concussions, meningitis, intestinal obstruction, appendicitis, brain tumours etc.

Dehydration caused by vomiting is a serious point of concern. Adults can detect symptoms of dehydration but children have a greater risk of becoming dehydrated, especially if they have diarrhoea, because they are often unable to communicate and express symptoms of dehydration. Signs of dehydration are dry lips and mouth, sunken eyes, rapid breathing or pulse, decreased urination (infants) and sunken fontanelle (infants).

Hyper-emesis gravidarum – recurrent vomiting in the pregnancy, mother feels fluid and mineral imbalances which can endanger her life or that of her unborn child.

Rarely, excessive vomiting can tear the lining of the oesophagus also known as a Mallory-Weiss tear. If the oesophagus gets ruptured, it is called Boerhaave’s syndrome and is a medical emergency.
Read related: Chardi Roga Chikitsa: Ayurvedic Treatment For Vomiting, Limitations

When to call for a doctor in case of vomiting?

• When the nausea lasts for more than a few days
• If there is a possibility of getting pregnant (associated with nausea for more than few days)
• If the home treatment is not working
• Presence of severe dehydration known injury (head injury, infection etc)
• Adults – Vomiting occurs for more than one day, diarrhoea and vomiting lasting for more than 24 hours or presence of dehydration symptoms
• In infants or child under 6 years of age – Vomiting lasts for more than few hours, diarrhoea combined with vomiting signs of dehydration, fever or when there is no urination for 4-6 hours
• Child above 6 years of age – if vomiting lasts for one day, diarrhoea combined with vomiting lasts for more than 24 hours, signs of dehydration, fever higher than 101 degrees, child has not urinated for 6 hours or more

Seek immediate medical attention if the below said conditions are seen with vomiting –

• Blood in vomit
• Severe headache
• Stiff neck
• Lethargy
• Confusion
• Decreased alertness
• Severe abdominal pain
• Diarrhoea
• Rapid pulse
• Rapid breathing

Treatment

Antiemetic (drug effective against vomiting and nausea) – anticholinergics, antihistamines, dopamine antagonists, serotonin antagonists and cannabinoids are used as antiemetics
Drink gradually larger amounts of clear liquids, water, restore fluid balance in the body
Avoid solid food until the vomiting episodes have passed away
Oral rehydrating solution – to prevent and treat dehydration (if vomiting or diarrhoea last more than 24 hours)
Eating some crackers before getting out of bed or high protein snack before going to bed (less meat or cheese) – for pregnant women experiencing morning sickness.
Click to consult Dr Raghuram Y.S. MD(Ayu) – email / skype