Though you may feel under the weather and legitimately unable to come to work due to illness, you should be prepared for scepticism from your boss when you call in sick. According to CNN, one-third of workers have taken a day off when they weren't really sick, leading managers to question whether many sick calls are actually genuine. While you can't stop your manager from being sceptical, you can be professional when you call in sick.
Choose a professional method of communication to relay your sick news. In most work situations, it is standard to call your manager directly on the telephone and let him know you will need to take a sick day. This is especially the case if you typically come into the office around the same time as your manager and have no responsibilities that require you to be there earlier than him. If your manager usually comes into the office after you, and you don't have a phone number to reach him at before he gets to the office, leave a message on his office voicemail first thing in the morning.
Follow your voice message with an e-mail letting your boss know you will not be in the office prior to his arrival. He may read his work e-mail on a home computer or mobile device and will get your message before he leaves for the office.
Contact your human resources department and direct co-workers to let them know you will be out sick. If your place of work does not have an onsite human resources division, contact an office secretary or a lower-level manager. Letting multiple people at your company or organisation know that you are calling in sick will demonstrate that you made multiple attempts to alert your workplace of your absence.
Avoid overemphasising the fact that you are sick. According to CNN, there's no need to "oversell" your sickness to your boss since this can make it seem like you are not actually as sick as you say. Keep your phone call to your manager short and concise, and try to keep your coughs or sniffles to a minimum.
Update your boss about your health progress later in the day. This will help him assess if you will be in the office the next day, and will give him a sense of how he should prepare if you will be absent for more than one day. Avoid resorting to e-mail first. Use the telephone to call your boss about any health updates. If he does not answer, leave a voice message and follow it with an e-mail.