There are three main systems involved in voice production and each system is equally important.  Voice production involves the synchronisation of over 100 muscles in the body, it is dynamic and complex. It involves breathing using your diaphragm. As air moves up from the lungs, it brings the vocal cords together causing the vibration of the vocal cords to make sounds. These are then shaped into words by the cavities of the mouth and nose. 

Our voice is designed to last us a lifetime with due care and respect, however a range of variables can affect it. If your vocal cords become inflamed, develop growths or become paralysed they won’t work correctly and you may develop a voice disorder.

We know that some people are more likely to develop voice problems due to physical, emotional, personality, occupational factors and illness.  Vocal changes such as hoarseness (breathy, rough, raspy or strained sounding voice) or vocal fatigue (voice sounds normal but may be effortful to produce daily and very tired after prolonged speaking) are the most obvious initial signs of a voice problem.

Causes of voice problems/disorders can include:

• Illness e.g. colds or Upper respiratory tract infections
• Inflammation caused by gastroesophageal reflux (sometimes called acid reflux, heartburn, or GERD) or allergies e.g. sinus (post nasal drip)
• Vocal misuse and overuse (includes throat dehydration, talking over background noise, whispering, yelling, constant throat clearing, constant effortful vocal projection, smoking)
• Scarring from neck surgery or trauma of the front of the neck (Growths on the vocal folds, such as vocal nodules or laryngeal papillomatosis)
• Laryngeal lesions
• Cancer of the larynx
• Neurological diseases (such as spasmodic dysphonia, vocal fold paralysis or Parkinson's disease).
• Psychological trauma/ Stress
• Aging

Laryngitis is temporary swelling of the vocal folds due to a cold, or acute upper respiratory infection, or allergies.  It is the most common cause of hoarseness.  Your doctor will treat laryngitis according to its cause,e.g. For (1) a cold or upper respiratory infection, your doctor might recommend rest, fluids, and nonprescription pain relievers. (2) Allergies might be treated similarly, with the addition of over-the-counter allergy medication.

Cheering at sporting events, speaking loudly with force in noisy situations, talking for too long without resting your voice, singing loudly, or speaking with a voice that's too high or too low can cause temporary hoarseness.Treatment usually includes resting, reducing voice use, and drinking lots of water, which should help relieve hoarseness from misuse or overuse. 

Sometimes people whose jobs depend on their voices—such as teachers, singers, or public speakers—develop hoarseness that won't go away. 

If you use your voice for a living and you regularly experience hoarseness, your doctor might suggest voice therapy by seeing a Speech & Language Therapist. In voice therapy, you'll be given vocal exercises and tips for avoiding hoarseness by changing the ways in which you use your voice.

GERD, commonly known as heartburn can cause hoarseness as stomach acid rises up the throat and irritates the tissues. Usually hoarseness caused by GERD is worse in the morning and improves throughout the day. In some people, the stomach acid rises all the way up to the throat and larynx and irritates the vocal folds. This is called laryngopharyngeal reflux (LPR). LPR can happen during the day or night. Some people will have no heartburn with LPR, but they may feel as if they constantly have to cough to clear their throat and they may become hoarse. GERD and LPR are treated with dietary modifications and medications that reduce stomach acid.

These are benign (noncancerous) growths within or along the vocal folds. Vocal nodules are sometimes called "singer's nodes" because they are a frequent problem among professional singers. They form in pairs on opposite sides of the vocal folds as the result of too much pressure or friction, much like the way a callus forms on the foot from a shoe that's too tight. A vocal polyp typically occurs only on one side of the vocal fold. A vocal cyst is a hard mass of tissue encased in a membrane sac inside the vocal fold. 

The most common treatments for nodules, polyps, and cysts are voice rest, voice therapy, and surgery to remove the tissue.

This occurs when a blood vessel on the surface of the vocal fold ruptures and the tissues fill with blood. If you lose your voice suddenly during strenuous vocal use (such as yelling), you may have a vocal fold hemorrhage. Sometimes a vocal fold hemorrhage will cause hoarseness to develop quickly over a short amount of time and only affect your singing but not your speaking voice. Vocal fold hemorrhage must be treated immediately with total voice rest and a trip to the doctor.

This is a voice disorder that occurs when one or both of the vocal folds don't open or close properly. It can be caused by injury to the head, neck or chest; lung or thyroid cancer; tumors of the skull base, neck, or chest; or infection (for example, Lyme disease). People with certain neurological conditions e.g. stroke, may also experience this. In many cases, however, the cause is unknown. 

Vocal fold paralysis is treated with voice therapy and, in some cases, surgery.

Diseases and disorders which affect areas of the brain that control muscles in the throat or larynx can also cause hoarseness. Hoarseness is sometimes a symptom of Parkinson's disease ( due to reduced breath support), or a stroke. Spasmodic dysphonia is a rare neurological disease that causes hoarseness and can also affect breathing. Treatment in these cases will depend upon the type of disease or disorder. 

These can both cause hoarseness. Hoarseness may sometimes be a symptom of laryngeal cancer, which is why it is so important to see your doctor if you are hoarse for more than three weeks. Hoarseness is also the most common symptom of a disease called recurrent respiratory papillomatosis (RRP), or laryngeal papillomatosis, which causes noncancerous tumors to grow in the larynx and other air passages leading from the nose and mouth into the lungs.

• Does your voice sound hoarse or raspy?
• Does your voice sound deeper/lower than it used to be?
• Does your throat feel tight,raw or sore?
• Are you experiencing discomfort or pain in your throat?
• Does speaking require increased effort (especially if you have to talk for long periods)?
• Do you clear your throat frequently?
• Have you experienced reduced pitch range while singing(difficulty reaching the high notes)?

Or

• Are you aware of a change in your normal voice quality that is persisting for longer than two - three weeks (in the absence of a cold or obvious infection)?

•  Your Doctor will then examine you to determine any underlying cause of these changes and recommend if you need to be referred to an Ear, Nose and Throat Specialist. (ENT) 

• An ENT may visualise your larynx using the specialist investigations as detailed below.

• Laryngoscopy. This allows a SLT or Doctor to view the throat. With indirect laryngoscopy, the healthcare provider holds a small mirror at the back of the throat and shines a light on it. With fiberoptic laryngoscopy, a thin, lighted scope called a laryngoscope is used. The scope is put through your nose down into your throat, or placed directly down into your throat.  
• Laryngeal electromyography, or EMG. This test measures electrical activity in the muscles of the throat. A thin needle is put into some of the neck muscles while electrodes send signals from the muscles to a computer. This can show nerve problems in the throat. 
• Stroboscopy. This test uses a strobe light and a video camera to see how the vocal cords are vibrating during speech.

Imaging tests. X-rays and MRI can show growths or other tissue problems in the throat.

• SLTs and ENTs frequently collaborate and work together to help people with voice problems. 
• ENTs diagnose voice disorders or structural changes and provide treatment if necessary. In a minority of people surgery may be needed.
• ENTs regularly and routinely refer you to see a Speech and Language Therapist who can help you improve how you use your voice. An ENT report is required by the Speech & Language Therapist in advance of issuing an initial Voice Therapy appointment.
• Some Specialist Voice Clinicians work directly within Hospital ENT Departments. Frequently SLTs consult with ENTs, neurologists and gastroenterologists regarding diagnosis and treatment.

• Drink plenty of water, 6-8 glasses, sipping regularly throughout the day. Because the vocal cords vibrate several hundred times per second when you speak and even more when you sing. Drinking water helps thin out the mucus that lubricates and protects your vocal cords as they vibrate.
• Reduce your tea/coffee or alcohol intake,as these can cause dehydration, 
• Keeping hydrated will also prevent you having to clear your throat frequently and further irritate your throat. 
• Use a humidifier in your home, especially in winter (when central/oil heating is on for long periods) or in dry climates. 
• Avoid or limit use of medications that dry out the vocal folds, including some common cold and allergy medications. If you have voice problems, ask your doctor which medications would be safest for you to use.

• Don't smoke, and avoid second-hand smoke. Smoke irritates the vocal folds.

• Include plenty of whole grains, fruits, and vegetables in your diet. These foods contain vitamins A, E, and C. They also help keep the mucus membranes that line the throat healthy.
• Wash your hands often to prevent getting a cold or the flu.
• Get enough rest. Physical fatigue can have a negative effect on voice.
• Exercise regularly as it increases stamina and muscle tone. Correct posture and breathing, is necessary for proper speaking.
• Exercise can help relieve stress. Other activity ideas to promote relaxation may include : yoga, pilates, mindfulness and progressive relaxation. 
• If you have persistent heartburn or GERD (gastro-eosophageal reflux),talk to your doctor about diet changes or medications that can help reduce flare-ups. Avoid eating spicy foods. Spicy foods can cause stomach acid to move up into the throat area. 
• Avoid mouthwash or gargles that contain alcohol or irritating chemicals.
• Consult your Doctor, if you have any signs of  low grade infections in the nose, sinuses, tonsils and gums.

• Try not to overuse your voice. Avoid speaking or singing when your voice is hoarse or tired.
• Rest your voice when you are sick. Illness puts extra stress on your voice.

• Avoid using the extremes of your vocal range, such as screaming or whispering. Talking too loudly and too softly can both stress your voice.
• Maintain good posture. Practice good breathing techniques when singing or talking.Support your voice with deep breaths from the chest, and don't rely on your throat alone. Talking from the throat, without a supporting breath, puts a great strain on the voice.
• Practice simple warm-up exercises for the voice in advance of prolonged talking periods and practice cool-down techniques at the end of the day. 
• Avoid cradling the phone when talking. Cradling the phone between the head and shoulder for extended periods of time can cause muscle tension in the neck.
• Avoid persistent, deliberate throat clearing, if you can’t prevent it, make it as gentle as possible. Taking dry swallows or small sips of cold water can  help to suppress the urge to cough. Whispering should also be avoided. 
• Consider using a microphone when appropriate. In environments such as exhibit areas, classrooms, or exercise rooms, a lightweight microphone and an amplifier-speaker system can be of great help.