All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
No doubt, names have clear effects on the individuals. So, persons and things are affected by their names regarding beauty, ugliness, lightness, heaviness, etc.
Ibn al-Qayyim said: “Since names indicate particular meanings; therefore, the wisdom proves that there is a strong relation between names and their meanings.” (Refer to Zaad al-Mee’aad for an important chapter on this subject).
He also said in another book entitled Tuhfatul-Mawdood Bi Ahkaam al-Mawlood: “If you are keen to know the effects of names on their personalities, you may refer to the Hadeeth narrated by Sa’eed Ibn al-Musayyib from his grandfather who said: “I went to the Prophet and he asked me, “What is your name?” I replied, “My name is Hazn” (roughness). The Prophet said, “You are Sahl” (softness)'. Hazn said, 'I will not change the name with which my father has named me. Sa’eed said: 'We have had roughness (in character) ever since.”
Moreover, the Prophet used to love good names of people, places, tribes, hills, etc. and hated their bad names. He used to take good omen from good names as he did in al-Hudaybiyyah treaty. When Suhayl ibn Amar came to talk, he said to his companions: “Your matter will become easy. Once he was passing by two hills in a journey and enquired about their names. He was told, 'Fadhih (shameful) Mukhzi (disgraceful)'. He turned away from them and did not pass by them.”
Once the Prophet asked people to milk a sheep. One of them got up to milk and the Prophet asked his name; he said, Murrah (bitter). The Prophet said: “Sit down”. Then another person got up to milk and he asked his name, and he said: Harb (war). He told him, 'Sit down'. Then, a third person got up to milk the sheep, he asked his name, he said, Ya’eesh (lives long). Then the Prophet allowed him to milk the sheep.”
It is narrated in Jameh Ibn Wahab that “A baby was brought to the Prophet and he asked his name. They said: as-Sayyib (abandoned). The Prophet said: “No, but his name is Abdullah (slave of Allah).” The narrator said: “But the people used to call him by the other name, so he did not die till he became insane.”
There is proverb in Arabic language: 'Misfortune can result from utterances.'
However, every name has some effects on the personality. If one is named Hazen (roughness) or Sayyib (abandoned) or Thaqeel (heavy), or ‘Aleel (sick), or Murrah (bitter), he will have some of its effects and the qualities of roughness, bitterness, etc., in his personality.
Therefore, one should choose good names and avoid bad names.
Changing one's name is permissible or even desirable as the Prophet changed names of some of his male and female companions.
Finally, if your sick son is named by a name that suggests sickness, or any other bad meanings, then it is better to change that name. If there is no such meaning, then changing the name does not make sense.
In addition, we draw your attention to the point that giving bad names is disliked; similarly, it is also disliked to give names that indicate glorification or veneration, such as the names Taqiy that means (God fearing person), Saalih (righteous), Barrah (pious), etc. Sometimes it leads to bad meanings, like if you call out: “Is Takiy (god-fearing) or Saalih (good) there?” If he is not there, the response would be ‘no' and that could imply such “good” is not here. 'Islam', 'Salah', and 'Eeman' are also among the names that indicate glorification.
The dearest names to Allah are ‘Abdullah and Abdur-Rahman as reported in an Saheeh Muslim.
Allah knows best.