Why Does My Stomach Sound Hollow When I Slap It?

16 mins read

Last Updated on May 9, 2023

We’ve all experienced that hollow, drum-like sound when we playfully slap our stomachs. But why does this happen? And should we be concerned? This article will explore the mysteries behind stomach sounds, skull resonance, and the sensations we sometimes feel in our abdomen. Join us as we delve into the world of anatomy, medicine, and strange bodily sounds.

Anatomy of the Stomach and Abdomen

Stomach Layers and Structure

The stomach is a muscular, sac-like organ that plays a key role in digestion. It’s made up of three layers: the mucosa (innermost layer), the muscularis (middle layer), and the serosa (outermost layer). The muscularis is responsible for the contractions that churn and mix food with gastric juices, while the serosa protects the stomach and helps it maintain its shape.

Abdominal Cavity and Organs

The abdominal cavity houses the stomach and several other organs, including the liver, pancreas, intestines, and spleen. These organs are surrounded by a protective layer called the peritoneum, which helps to lubricate and cushion them. The abdominal cavity also contains air and fluid, which can create various sounds and sensations.

Tympany: The Drumming Sound

Gas and Air in the Gastrointestinal Tract

The hollow, drum-like sound you hear when you slap your stomach is known as tympany. It’s caused by the presence of gas and air in your gastrointestinal (GI) tract. When you eat, drink, or swallow saliva, you inevitably swallow some air as well. When struck, this air can get trapped in your stomach and intestines, creating a resonant space that produces the tympany sound.

Stomach Tapping: A Diagnostic Technique

Doctors often use a technique called percussion, or tapping, to assess the presence of gas, fluid, or masses in the abdomen. By tapping different areas of the abdomen and listening for changes in pitch, they can gain valuable information about the underlying organs and structures. Tympany is typically considered a normal finding, as it indicates the presence of gas in the GI tract.

Tympany in the Abdomen: Normal or Abnormal?

In most cases, tympany in the abdomen is a normal finding. However, you should consult your doctor if you experience excessive tympany or abdominal discomfort. In some cases, excessive gas or bloating could indicate an underlying condition, such as irritable bowel syndrome, lactose intolerance, or even an obstruction in the GI tract.

Why Does My Stomach Sound Like Water When I Move It?

Fluid Accumulation and Movement

If your stomach sounds like it’s sloshing with water when you move, it could be due to fluid accumulation in your abdomen. This can occur for various reasons, including inflammation, infection, or injury. Fluid can also accumulate in the peritoneal cavity, the space surrounding the abdominal organs, causing a condition called ascites.

Normal Bowel Sounds

It’s also worth noting that some sloshing sounds in your abdomen can be completely normal. Your intestines are constantly moving and churning to digest food, and this process can produce a range of gurgling, rumbling, and sloshing sounds known as bowel sounds.

The 4 Types of Bowel Sounds

Bowel sounds are the noises produced by the movement of food, fluids, and gas through the gastrointestinal tract. They can be categorized into four main types:

  1. Normal bowel sounds are typical gurgling and rumbling sounds that occur every few seconds to minutes. They’re generally soft and non-disturbing.
  2. Hypoactive bowel sounds are slower or quieter than normal and may indicate constipation, anesthesia effects, or certain medications.
  3. Hyperactive bowel sounds: These are loud, frequent, and high-pitched sounds that may be heard in conditions such as diarrhea, gastroenteritis, or gastrointestinal obstruction.
  4. Absent bowel sounds: The complete lack of bowel sounds could indicate a serious medical issue like a bowel obstruction or ileus. Medical attention should be sought immediately in such cases.

The Hollow Sound of the Skull

Skull Anatomy and Resonance

The skull is made up of several bones that are connected by sutures, which allow for slight movements and expansion. The skull’s structure and the air-filled sinuses within it create a natural resonance chamber that produces a hollow sound when tapped or knocked.

Sinuses and the Hollow Feeling

The hollow sound of the skull can also be attributed to the sinuses, which are air-filled cavities in the facial bones. These sinuses help to humidify the air we breathe, produce mucus to trap particles and give the resonance of our voice. When you tap on your skull or experience sensations like echoey ears or white noise in your head, it’s often due to the natural resonance created by the sinuses.

Exploring Stomach Hardness and Sensations

Differentiating Fat from Muscle

A hard stomach can be the result of strong abdominal muscles or the presence of excess fat. It’s important to differentiate between the two, as carrying excess abdominal fat can have negative health implications. A simple way to check is by pinching the skin on your abdomen. If you can easily pinch a layer of fat, it’s likely that the hardness is due to fat rather than muscle.

Abdominal Bloating and Distension

Another reason for stomach hardness could be abdominal bloating or distension, which can occur due to gas, fluid retention, or constipation. This can cause your abdomen to feel hard, tight, and uncomfortable. If you experience persistent bloating or distension, it’s important to consult your doctor to rule out any underlying medical issues.

The Stomach Feels Hollow After Eating

Feeling a sense of hollowness in the stomach after eating could be due to various factors, including the type of food consumed, the speed at which you ate, or even stress and anxiety. To minimize this sensation, try eating smaller meals, chewing your food thoroughly, and practising relaxation techniques.

Hollow Feeling in the Upper Abdomen

A hollow feeling in the upper abdomen may be related to the stomach’s natural anatomy and surrounding organs. However, if this sensation is accompanied by pain, discomfort, or other symptoms, it’s important to consult your doctor to rule out any underlying medical issues.

Concerning Stomach Noises and Sensations

When to Worry about Stomach Noises

While stomach noises are generally harmless and normal, there are situations when you should be concerned. If the noises are accompanied by severe pain, persistent vomiting, diarrhea, fever, or significant weight loss, it’s crucial to seek medical attention, as these could be signs of an underlying health issue.

Identifying the Cause of Abdominal Discomfort

If you’re experiencing abdominal discomfort along with stomach noises, it’s important to consider the possible causes. Common culprits include indigestion, gas, constipation, food intolerances, or overeating. If you’re unable to pinpoint the cause or if the discomfort persists or worsens, consult your doctor for a proper evaluation.

Stomach Beating Like a Heart: When to Be Concerned

If your stomach feels like it’s beating or pulsating, it could be due to the normal movement of blood through the abdominal aorta, the large blood vessel that runs through your abdomen. This sensation is more noticeable in thin individuals or when lying down. However, if the pulsating sensation is accompanied by pain, swelling, or other concerning symptoms, seek medical attention, as it could be a sign of an abdominal aortic aneurysm or another serious condition.

Belly Fat Characteristics

Soft or Hard Belly Fat: What’s the Difference?

Belly fat can be classified into subcutaneous fat and visceral fat. Subcutaneous fat is the soft, pinchable fat found just beneath the skin, while visceral fat is the harder, deeper fat that surrounds your organs. Visceral fat is considered more dangerous, as it has been linked to an increased risk of various health issues, such as heart disease, type 2 diabetes, and certain cancers.

Big Belly Without Fat: Possible Causes

Other factors could be at play if you have a large abdomen but can’t seem to find much fat when pinching your skin. Some potential causes include bloating, fluid retention, weak abdominal muscles, or even an underlying medical condition. If you’re concerned about your abdominal size, it’s best to consult your doctor for an evaluation.

The Role of Abdominal Tapping in Medical Examinations

Purpose of Tapping the Abdomen

During a physical examination, doctors may tap or percuss the abdomen to assess the presence of gas, fluid, or masses within the abdominal cavity. The different sounds produced can help them identify potential medical issues.

What Doctors Look for When Tapping on the Stomach

When tapping on the stomach, doctors listen for the characteristic tympany sound, indicating gas presence. They also pay attention to any areas of dullness, which could suggest fluid accumulation, a mass, or an enlarged organ.

Hollow Sounds in Other Parts of the Body

Hollow Sounds in the Chest

The chest cavity can also produce hollow sounds when tapped, especially in areas where air-filled spaces, like the lungs, are located. This is a normal finding during a physical examination.

Examining the Hollow Sound in Joints

Some joints, particularly the knee, can produce a hollow sound when tapped due to the presence of a fluid-filled cavity called the joint capsule. In some cases, this sound can indicate the presence of excess fluid, which could be a sign of an underlying medical issue.

By exploring these additional headlines, we can further understand the significance of hollow sounds in the human body and their relation to our overall health.


Our bodies are complex and fascinating, producing a range of sounds and sensations that can be both intriguing and, at times, concerning. In most cases, the hollow sounds and sensations we experience in our stomachs and skulls are normal and harmless. However, paying attention to our bodies is always important and seeking medical advice when necessary.

Frequently Asked Questions

Why does my stomach sound hollow when I slap it?

The hollow sound, known as tympany, is due to the presence of gas and air in your gastrointestinal tract. This is a normal finding in most cases.

Should I be worried about stomach noises?

Stomach noises are typically harmless, but if they’re accompanied by severe pain, persistent vomiting, diarrhea, fever, or significant weight loss, seek medical attention.

Why does my skull sound hollow?

The hollow sound of the skull is due to its structure and the air-filled sinuses within it, which create a natural resonance chamber.

What does it mean when your stomach is hard?

A hard stomach could be due to strong abdominal muscles, excess fat, or abdominal bloating and distension.

Is it normal for my stomach to sound like water when I move it?

Some sloshing sounds in the abdomen can be normal, resulting from the movement of food, fluids, and gas through the gastrointestinal tract. However, excessive sloshing could indicate fluid accumulation, which warrants medical evaluation.

What are the 4 types of bowel sounds?

The 4 types of bowel sounds are normal, hypoactive, hyperactive, and absent bowel sounds.

Why do my ears feel echoey?

Echoey sensations in your ears can be due to the natural resonance created by the sinuses. However, if the sensation is persistent or accompanied by other symptoms like pain or hearing loss, consult a healthcare professional.

Should belly fat be soft or hard?

Belly fat can be either soft or hard, depending on its type. Soft, pinchable fat is subcutaneous fat found just beneath the skin, while hard, deeper fat is visceral fat that surrounds your organs. Visceral fat is considered more dangerous and has been linked to various health issues.

Are bones supposed to sound hollow?

Yes, bones, especially the skull, can sound hollow due to their structure and the presence of air-filled spaces like sinuses, which create a natural resonance chamber.

When should I be worried about the hollow feeling in my stomach?

If the hollow feeling in your stomach is accompanied by pain, discomfort, or other concerning symptoms, it’s important to consult your doctor to rule out any underlying medical issues.

About The Author

Gauthier Daniau is a freelance problem solver. He first discovered his knack for trouble-shooting when he was still in diapers - and hasn't looked back since. When he's not slaying zombies or internet ninjas, GAUTHIER enjoys working with animals of all shapes and sizes. He's also something of a social media expert and loves to get lost in numbers and figures.