There are a number of reasons that could be causing the muscle spasms in your throat when you are trying to swallow. They range from an inflammation of your larynx or voice box to an enlarged thyroid cartilage, or even the effects of gastroesophageal reflux disease or GERD. Having any of these problems requires that you visit the doctor immediately for a proper diagnosis.
Laryngitis is an inflammation of the voice box and can occur due to an allergy or an infection like a sore throat. In an inflammation of a certain part of the body, that body part will swell up as a reaction that is part of the body’s immune response. This could be one of the reasons, however, if you have not suffered an upper respiratory tract infection recently, this can be ruled out as a cause. Another possibility is that you might have a malformation in your throat caused by the cartilage of your thyroid gland. This is usually characterized by a clicking sound that occurs when the neck is turned, along with some difficulty of swallowing. If this is the case, then the mechanism at work here is that the thyroid cartilage is rubbing against the larynx area and its muscles. While this is not a dangerous situation in any way, it can be annoying to the patient. This can be corrected by surgically correcting the size of the cartilage to avoid the rubbing together of the two parts and this is a surgery that leaves no side effects. This condition is not normal and can usually occur after some kind of trauma to the throat. Gastroesophageal reflux disease is a condition in which the lower esophageal sphincter that opens from the food pipe to the stomach refuses to close shut. This condition results in stomach acids coming up to the throat especially when the person who has the disorder is in a horizontal position, as one would be during sleep. The stomach acids can then attack the larynx and cause an inflammation. Treatment for this is a course of antacids and a lifestyle change that starts from dietary changes to a lifelong dependence on acid inhibitors.
If the condition has been chronic and bothering you for a while, the final possibility which you need to accommodate for is the possibility of a tumor in the laryngeal area. This can be confirmed with a serious of scans and a soft tissue X ray in the region for any growths that appear to fit the description of a tumor.