Both bradypnea and tachypnea are signs that point towards breathing problems, such as either a slow or elevated breathing rate.

Bradypnea and tachypnea are signs that point toward breathing problems. Bradypnea refers to abnormal slow breathing (respiratory) rate, whereas tachypnea refers to an elevated breathing rate in which the breathing is shallow.

For an adult, the normal breathing rate is typically between 12 and 20 breaths per minute. A respiration rate below 12 is typically known as bradypnea and that over 20 breaths per minute while resting is known as tachypnea.

What is the normal respiratory rate in children and adolescents?

Levels of bradypnea and tachypnea vary among different age groups because of differences in the normal respiratory rate in each group.

0 to 12 months
30 to 60

One to two years
24 to 40

Three to five years
22 to 34

6 to 12 years
18 to 30

13 to 17 years
12 to 16

What are the signs and symptoms of bradypnea?

Signs and symptoms that accompany bradypnea depend on what has caused it, but may include:

• Dizziness
• Decreased energy
• Weakness
• Fainting
• Chest pain
• Shortness of breath
• Memory impairment
• Confusion
• Lethargy
• Sleep problems
• Nausea
• Vomiting

What are the signs and symptoms of tachypnea?

Tachypnea is a sign that your body is trying to correct some other problem by breathing rapidly. 

Other signs and symptoms that may accompany tachypnea include:

• Shortness of breath
• Chest pain
• Sharp pain when breathing in
• Pressure in the chest that worsens over time
• Cyanosis (blue discoloration of the skin or lips)
• Rapid heart rate
• Confusion
• Dizziness

What are the causes of bradypnea?

Bradypnea may be caused by any of the conditions that affect the heart and your overall metabolism, as well as medications and other causes, such as:

• Age-related heart tissue degeneration
• Heart attack or heart disease that causes damage to the heart tissue
• Hypertension (high blood pressure)
• Congenital heart defect (heart problem present at birth such as mitral valve stenosis)
• Myocarditis (inflammation of the heart muscle)
• Hypothyroidism (an underactive thyroid gland)
• Inflammatory disease such as:
  • Lupus
  • Rheumatic fever
• Obstructive sleep apnea (frequent cessation of breathing during sleep)
• Hemochromatosis (buildup of iron in the organs)
• Electrolyte imbalance
• Opioid overdose
• Medications such as:
  • Calcium channel blockers (diltiazem and verapamil)
  • Beta-blockers (atenolol and metoprolol)
  • Alpha/beta-adrenergic blockers (carvedilol and labetalol)
  • Digoxin
  • Antidepressants (fluoxetine, fluvoxamine, and paroxetine)
• Certain other conditions such as barbiturate overdose, deep anesthesia, brainstem injury, and deep sleep

What are the causes of tachypnea?

Tachypnea is the response of your body to take in more oxygen quickly when oxygen levels in the body decrease too low or carbon dioxide levels increase too high. The most common causes of tachypnea are physical exertion and anxiety.

Certain medical conditions can lower your oxygen levels or increase your carbon dioxide levels, including:

• Asthma
• Pneumonia
• Chronic obstructive pulmonary disease
• Pleural effusion (collection of excess fluid between outer coverings of one or both the lungs)
• Pneumothorax (a collapsed lung)
• Pulmonary embolism (blood clot in a lung’s artery)
• Pulmonary fibrosis (lung tissue becomes damaged and scarred)
• Cystic fibrosis (a genetic disorder that often affects multiple organ systems of the body, including the lungs)
• Allergic reactions
• Lung cancer