The Archangels are God's Emissaries of Divine light.
These powerful beings of light are considered the most important messengers in the celestial hierachy. The Archangels oversee our Guardian Angels. The Archangels and Angels are the most closest to mankind.
Archangels provide special support, they each have specialties and divine attributes as faith, hope, power, protection,  healing,  grace,  forgiveness,  mercy and compassion,  discernment, and harmony...  thus providing us with  peace, comfort,  balance, fulfillment,  divine guidance, love and joy!
When you have a health need, you seek out a specialist. Look at the Archangels as your specialists assisting you with your needs. You can always ask for support to any of the Archangels, but you can ask and work with particular Archangels who can minister in a specific need. Just ask and they will come to your aid.
Archangels love to be called upon because serving you is to serve God. Archangels are strong, kind and loving, and they are egoless.
There are seven Archangels who are mentioned in the Book of Revelation. The Bible names four of the Archangels: Michael, Gabriel, Raphael, Uriel. Ancient Jewish texts mention 15 Archangels.
The following are some of the Archangels with their specialties. Archangels names end in "El" which means 'from God'.
Michael  'He who is like God '  -  Archangel of Protection, releases fear and dispels negativity. Considered the most powerful of all the Archangels
Gabriel   'Messenger of God' -  Calms and gives confidence, also supports writers and teachers. Helps parents with children.
Raphael   'He who heals'  - in charge of healing, emotional, physical and spiritual.
Uriel   'God is light' - Widsom and philosophy, illuminates us with new ideas.

Raguel  'Friend of God'  - Harmony to all relationships, heals misunderstandings. 

Chamuel  'He who sees God' - Helps with anxiety, brings peace, and helps find lost objects as well as people.

Zadkiel   'Freedom of God' - Helps transmute lower energies to higher frequencies of energy. Power of compassion, forgiveness and freedom.

Jophiel  'Beauty of God' - Heals chaotic situations, brings order and beauty and joy and organization to our environments. 

The whole purpose of the Archangels is to support us and serve us in any area of our life. Your Guardian Angel(s) is/are with you watching over you at all times. 

But you can call upon the Archangels at any time when you really need that extra help, extra power to take action on an important endeavor, or healing. 

Remember that you have free will and the Angels will not interfere without your permission. Unless there is a life threatening situation, they will then assist immediately. 

'Ask and you Shall Receive' 

What a priviledge to know and how blessed we are, that we have the Archangels' love and support with just a thought, a prayer, or best of all a few words...just say Angels come help me!